"None" and "No Indications of Clarity Enhancement" are found in emerald identification books. Although both appear to be "no processing," their meanings are completely different. This article, based on primary materials from GIA and LMHC (Laboratory Terminology Unification Committee), will explain the definitions and uses of the two, their relationship with F1/F2/F3, and pitfalls when purchasing and selling. This is a must-read guide for those who buy and sell non-oil emeralds.
Supervised | SUPERVISED BY
Takazo Saito
Selby Co., Ltd.
Buyer for the Komehei Group's only company specializing in jewelry. In addition to supervising the EC/SNS/Ruth/product production department, he is also in charge of purchasing rare stones. He specializes in determining authenticity and evaluating value, and works to protect consumers and improve market transparency by disseminating gemological information.
Summary in 30 seconds
- “None” = No fissures (cracks) reaching the surface are observed.A notation used only for stones. In the first place, there is no gap that can be filled.
- “No Indications of Clarity Enhancement” = No clear signs of clarity enhancement found in the report results.This is the notation used for stones (Fisher does exist). This result corresponds to the "No or Insignificant Clarity Enhancement" classification in the legend of the GIA report.
- In other wordsThe difference between the two is not the amount of oil, but the presence or absence of cracks.. This is where all misunderstandings start.
- The notation of GIA is “No or Insignificant Because the classification includes “Clarity Enhancement”,"No Indications" = no guarantee of completely zero oil。
- The identification book isShows only the status at the time of inspection. Oil impregnation can be removed and reapplied, so old certificates are not proof of current status.
- These two also have different evaluations in the market.Based on actual examples that SELBY has dealt with so far and experience at purchasing and sales sites, there are cases where "None" is evaluated 20 to 30 times higher than "No Indications" if the conditions are the same.. The reason is that "None cannot be created by washing."
What is "non-oil emerald"?
Oil-free emerald is an industry term for emeralds that have not been treated with clarity enhancement, which involves impregnating the cracks with oil or resin. Identification organizations such as GIA do not use the term "oil-free."
Due to the nature of the production environment and mining method, most emeralds contain fissures that reach the surface. In the comments section of the Emerald Report, GIA notes that many stones have surface-reaching characteristics due to their growth conditions and recovery methods, making clarity enhancement a common business practice.
By infiltrating these cracks with oil or resin, the difference in refractive index between the cracks and the stone body becomes smaller, reducing light scattering and making the cracks harder to see. As a result, the transparency increases and you can see even the colors better. Stones that have not undergone this treatment are called "non-oil" or "no oil" in the market.
However, this is important."Oil-free" is not a term in the identification book, but is only a name given by the distributor.Different words with different definitions are written in the identification report, such as "None," "No fissure filling," and "No indications of clarity enhancement." This discrepancy in translation directly leads to misunderstandings among consumers.
Conclusion: The difference between None and No Indications is “presence or absence of cracks”
In both the LMHC regulations and the classification chart printed in GIA's Emerald Report, "None" is used for stones with no surface-reaching fissures, and "No Indications of Clarity Enhancement" is used for stones with fissures. The difference between the two is not the amount of oil, but whether or not the cracks themselves are observed.
This usage is clearly stated in Information Sheet #5 “Emerald – fissure filling / clarity enhancement” of the LMHC (Laboratory Manual Harmonization Committee), of which GIA is a member. The sheet specifies how to describe emeralds that are free of fissures or do not show signs of filling with oil, resin, wax, or other fillers, and lists the following words to be included in the "Further information" column:
- None — Limited by footnote to “use only if no phishers are observed”
- No fissure filling ／ No indications of clarity enhancement/modification — Limited by footnote to “use only if phishers are observed”
In other words, even though they both mean "no trace of processing," these two words have a clear division of roles. The understanding that "None" has less oil is incorrect. Correctly, please understand it as follows.
- None= Condition in which fisher to be filled is not observed
- No Indications of Clarity Enhancement= A condition in which fisher is observed but no clear signs of clarity enhancement are observed.
The difference is not the amount of oil, but the nature of the stone. There is a reason for the phrase "no clear signs are observed." This is because this notation does not prove the complete absence of impregnating material. For more details“Even if there are no indications, it doesn’t mean there is no oil.”I will explain.
Understand the GIA/LMHC notation system at a glance
GIA's emerald report first divides the diamond into two categories based on whether there is a fisher or there are traces of filling, and if there are traces, the extent is quantified using F1, F2, and F3. It is a total of 5 stages system.
The classification table of the Emerald Report published by GIA has the following structure.
| stone condition | Report notation | fisher | Impregnation material | Understanding in Japanese |
|---|---|---|---|---|
| No Fissures Present | None | not observed | - (No target) | There is no crack itself. Confirmed examples are limited in SELBY handling practices. |
| No or Insignificant Clarity Enhancement |
No indications of Clarity Enhancement |
Yes | No obvious signs of clarity enhancement or negligible impact on appearance | Most of what is called "oil-free" in the market is this. |
| Quantification | F1(Minor Clarity Enhancement) | Yes | Few | There is only a slight effect on the appearance when viewed from the front. |
| Quantification | F2(Moderate Clarity Enhancement) | Yes | medium | Noticeable but not extreme effects. |
| Quantification | F3(Significant Clarity Enhancement) | Yes | many | The effect on appearance is obvious. |
Source:CLARITY ENHANCEMENT classification table printed in GIA Emerald Origin Report No. 5526246582 (published August 29, 2025)(Accompanied by Ruth handled by Selby Co., Ltd. Check the actual product), LMHC Information Sheet #5 “Emerald – fissure filling / clarity enhancement” (Version 6, May 2025/Joint regulation by 7 laboratories including GIA Laboratory), and GIA official FAQ “On a Laboratory report for a treated emerald, what does F1, F2 and F3 mean?”. GIA defines F1 as minor, F2 as moderate, and F3 as significant, with ``slight'' meaning that the impact on appearance when viewed from the front is slight, and ``noticeable'' meaning that the impact on appearance is obvious.
This classification table is printed on the certificate itself.
Surprisingly little known,This five-category correspondence table is printed directly as a legend on GIA's Emerald Report.I searched for the explanation page on the GIA official website but couldn't find it. This information can only be confirmed by seeing the actual certificate.
In the GIA Emerald Origin Report (No. 5526246582/published on August 29, 2025) handled by SELBY, there is a heading of "CLARITY ENHANCEMENT" under the comment section."NO FISSURES PRESENT → NONE" "NO OR INSIGNIFICANT CLARITY ENHANCEMENT → NO INDICATIONS OF CLARITY ENHANCEMENT" "QUANTIFICATION OF CLARITY ENHANCEMENT → F1 (MINOR) / F2 (MODERATE) / F3 (SIGNIFICANT)"I have confirmed that the table is printed.
Please note that the judgment results themselves are not in the table."TREATMENT" column at the top of the reportwill be listed in. In the case of this stone, it was "None". The table serves as a legend showing where the word falls within the five categories.When checking your certificate of authenticity, please first look at the TREATMENT column.
How does the judgment flow? (Flowchart)
Please note that LMHC's Information Sheet #5 is not Fisher's.When filling resin/wax into wide cracks or cavities (defects)are classified separately,C1 (Minor), C2 (Moderate), C3 (Significant)We have established another alphanumeric. It is different from the F scale, so if you see the C symbol on the identification book, do not confuse it.
Why “None” almost never exists
“None” is only given to emeralds in which no fissures reaching the surface have been observed. GIA specifies in its report that most emeralds contain features that reach the surface, making stones that meet this criteria exceptional.
In SELBY
For reference, here is an example of a Colombian emerald with a GIA "None" rating handled by SELBY. 0.84ct, 5.86 x 4.85 x 3.70mm, rectangular step cut. GIA Emerald Origin Report (No. 5526246582/Published August 29, 2025) Species: Natural Beryl, Variety: Natural Emerald, Geographic Origin: Colombia, andTREATMENT: None This is an individual rated as. In the practice of handling SELBY, there are only a limited number of confirmed cases of emeralds that fall under None.
As GIA itself notes in the comments section of the report, most emeralds have surface-reaching characteristics due to their natural growth conditions and collection methods. That's why clarity enhancement has become a common business practice.
On the other hand, it can be said that the condition of ``not a single crack reaching the surface'' is exceptional for a mineral called emerald. GIA states in a 1999 paper that the vast majority of natural emeralds, regardless of origin, contain fischer, which can affect their appearance once cut.
In addition, it is important to note that searching for Fisher itself is not easy. In the paper, GIA describes how gemologists can use 10x to 25x magnification and dark-field illumination to view from the table surface as well as from the sides and edges, along with fiber optic illumination and reflected light to determine the location, size, and depth of fissures."None" means that even after completing this procedure, not a single item was found.
Don't overestimate "None"
“None” isThis does not mean that it is highly transparent or has no inclusions.. GIA's Clarity Enhancement classification only evaluates the filler that reaches the surface, not the clarity grade of the stone as a whole. Inclusions that do not reach the surface (crystal and fluid inclusions, so-called jardins) are not included in the evaluation because they cannot be filled in the first place. Therefore, even if it is "None", there may be stones with many inclusions inside.
"No Indications" does not necessarily mean that the oil is zero.
This notation does not guarantee the complete absence of impregnating materials. GIA itself states in a peer-reviewed journal that if a very small amount of foreign matter is detected and it does not significantly affect the appearance, it can be determined that "no evidence of filling was detected."
This is the part that is most likely to be misunderstood due to the Japanese word ``non-oil''. The basis for this is the academic paper in which GIA published this classification system. GIA's McClure and colleagues published a study in the Winter 1999 issue of Gems & Gemology that examined approximately 500 filled emeralds using the GIA diamond clarity grading framework and provided the following criteria:
- If the size of the filled fissure is equivalent to diamond clarity VVS1 (extremely small compared to the size of the stone), it will not have a noticeable effect on the appearance of the emerald, so it will be classified as "no evidence of filling treatment detected".
- The premise is that"The presence of minute amounts of filler does not constitute 'enhancement' if appearance is not affected."The idea is that
- If a very small amount of foreign material is detected and it is determined that it does not significantly affect the appearance of the stone, the report can be ``No evidence of filling process detected.''
The same paper also"The presence of surface-reaching fissures does not necessarily mean that the emerald has undergone treatment."It is also clearly stated. Even if there is a large fissure, if there is only a small amount of foreign matter present, the treatment is classified as "minor (F1)".
This idea continues in the current report notation.In the classification chart printed on GIA's emerald report, the stone condition corresponding to "No Indications of Clarity Enhancement" is defined as "NO OR INSIGNIFICANT CLARITY ENHANCEMENT."The fact that the word “Insignificant” is explicitly printed on the GIA certificate is decisive. This statement is also confirmed in the report handled by SELBY (No. 5526246582/published August 29, 2025).
Key points to read:"No Indications of Clarity Enhancement" means that the examining gemologist, using standard testing techniques, found no evidence of filling that would affect appearance. It is not a physical measurement that guarantees zero down to one molecule. Understanding the nature of this notation before handling it is a sincere attitude for both sellers and buyers.
The identification report only talks about the “time of inspection”
Oil impregnation is a reversible process that can be removed and reapplied. The certificate of authenticity only describes the condition at the time of inspection and does not guarantee subsequent conditions. In the used market, this one point is the most important.
LMHC's Information Sheet #5 specifies that regarding impregnation treatments, a statement may be added to the report to the effect that ``clarity enhancement/modification is usually reversible and can be repeated at any time.This report only describes the condition at the time of inspection.''
Additionally, the sheet provides the following text as an option to replace "No indications of clarity enhancement."
At the time of testing, this gemstone exhibits no clarity enhancement. However, there are fishers that can be filled at any time. (Summary of options listed in LMHC Information Sheet #5, Version 6)
This is the wording that Rabo himself uses to convey to the reader, ``Currently we are oil-free, but that could change tomorrow.'' In addition, the footnotes on the same sheet are:For "highly washed emeralds with a large number of macroscopic phisers," there is an option to add a special note to the report mentioning those phisers.It is stipulated that It can be seen from this footnote that the laboratory incorporates the existence of "oil removal" into its operation.
GIA's official explanation for reintroducing filler type identification services in December 2024 also fits into this context. GIA offered emerald filler identification more than 20 years ago, but has shifted its focus to grade identification;“Recognizing that fillers can be removed, changed, and mixed”are listed. This means that the lab itself is based on the assumption that the state of the filler is not fixed.
How are F1, F2, and F3 determined?
F1, F2, and F3 are determined by comprehensively evaluating the size, spread, number, and position of the filled fissures, and the amount of filler contained therein, compared to the size of the stone and ``how it would have looked from the front if it had not been filled.'' Underlying is a GIA diamond clarity framework.
A 1999 paper by GIA's McClure et al. explains the design philosophy for this classification:
| classification | Comparable range in diamond clarity | meaning |
|---|---|---|
| (Not classified) | Equivalent to VVS1 | Because it is extremely small compared to the size of the stone, it is judged that it does not affect the appearance and is included in the category ``No evidence of filling treatment detected.'' |
| F1 (Minor) | Equivalent to VVS2 to VS2 | Little effect on appearance when viewed from the front |
| F2 (Moderate) | Equivalent to SI1~SI2 | Noticeable but not extreme effects |
| F3 (Significant) | Equivalent to I1 or less | The effect on appearance is obvious |
Source: McClure, S.F., Moses, T.M., Tannous, M., Koivula, J.I. (1999) "Classifying Emerald Clarity Enhancement at the GIA Gem Trade Laboratory," Gems & Gemology, Vol. 35, No. 4, pp. 176–185.
Four things you need to know
- It cannot be determined by numbers alone.GIA says a small filler fisher directly below the table has a greater impact on appearance than a large filler fisher along the girdle and can result in a heavier segment.
- Filler quality is not a major consideration.Cloudy or deteriorated fillers are basically treated the same as uniform, transparent fillers. The guideline for judgment is only the "estimated appearance before filling."
- Not a clarity grade.Inclusions that do not reach the surface are not evaluated.
- It is an inherently subjective system.GIA itself has made it clear that, like diamond grading, it is subjective and cannot be mastered just by reading or attending lectures; it requires hands-on experience. It should be read with the assumption that judgments may differ between laboratories and testers.
Degree of processing = not value
GIA clarifies in its paper that "Significant enhancement does not necessarily mean low value, and minor enhancement or no evidence does not necessarily mean high value." The degree of impregnation is only part of the value factor.
This is an important nail in the coffin for the no-oil faith from GIA itself. The paper states the following objectives:
- Degree of impregnation is only part of the value equation, which also includes color and weight
- The amount of internal inclusions that do not reach the surface greatly affects the value of the stone.
- Low-quality emeralds with a lot of inclusions will not increase in value even if they come with a “minor” certificate.
- Conversely, if an eye-clean stone receives a "significant" identification, it will have a negative impact on value compared to a less impregnated eye-clean stone.
- As many agree, the most important factor in determining the value of colored stones is color.
The paper provides a symbolic example.Even if a stone has many inclusions that are noticeable to the naked eye, it is judged to be "minor" if there are relatively few fillers reaching the surface. On the other hand, an eye-clean stone that appears to be of high quality at first glance actually has multiple large cracks hidden by the filling, and would look much worse without the filling, so it deserves a "significant" rating.--That's what it is.
Therefore, the correct reading is, ``When comparing two stones with almost the same conditions, the one with less impregnation is preferable.''Calf for relative comparisonis to use it as. It is not a stand-alone indicator of quality.
Filler type identification from December 2024 (Type A/Type B)
Starting December 15, 2024, GIA is offering optional filler “type” identification in the Emerald Report. However, what is identified is the type (oil-based or artificial resin), not the product name.
According to a GIA press release, if fillers are present, the report will indicate one of the following conclusions:
| Report notation | Content | Practical implications |
|---|---|---|
| Filler Type: A | May contain oils, waxes, natural resins | Strains traditionally considered to be highly tolerated |
| Filler Type: B | artificial resin | Strains that tend to have different market evaluations |
| unidentifiable | Clarity enhancement material cannot be identified at this time | Possible reasons include mixing, deterioration, and partial removal. |
Source: GIA official press release “GIA Enhances its Emerald Reports” (December 11, 2024, Carlsbad). Tom Moses, GIA's executive vice president and chief laboratory and research officer, explains that the changes are in response to market needs and have adapted the report to meet changing industry concerns about the degree and composition of emerald impregnation. The service will initially be provided free of charge.
This revision does not directly relate to "None" and "No Indications" stones. Because it's an option if filler is present. However,The reason why GIA temporarily stopped identifying filler types was because it recognized that ``fillers can be removed, changed, or mixed.''This background is an important supplementary line in understanding the scope of validity of the certificate of identification.
Non-oil from the perspective of used market and appraisal practice
"None" and "No Indications" are both stones that show no signs of impregnation on the identification report. However, their market valuations are not the same. As a result of SELBY's purchasing and sales practices, there is a price difference between the two that cannot be ignored.
Even if they are “non-oil”, the prices are not the same
From SELBY handling practices
Examples of what SELBY has handled so far and what we have experienced at purchasing and sales sitesIf conditions such as color, origin, size, internal condition, etc. are at the same level, an individual with a GIA "None" rating will have a higher quality than an individual with a "No Indications of Clarity Enhancement" rating.There are cases where it is rated 20-30% higher.
However, this is not a market price list, but rather an experience of SELBY's purchasing practices. Actual prices vary greatly depending on the color, size, and internal condition of each individual item, so please read this as a guide.
What I would like you to stop here is toThe thing about these two is that they are both ``oil-free.''Neither certificate shows any clear signs of clarity enhancement. However, the evaluation is different. SELBY's feeling is that the distinctions that have been explained so far in this article are also being considered when it comes to pricing.
Why is there a difference between “non-oil” products?
The reason for this can be logically derived from the contents of the primary sources reviewed so far in this article. At SELBY, we believe that the following three points are behind this.
| point of view | None | No Indications of Clarity Enhancement |
|---|---|---|
| Assumptions of durability | No cracks are observed reaching the surface. | There are cracks that reach the surface |
| Can it be made by washing? | I can't make it.Fischer does not disappear even after washing | It can be done in theory.This can be applied if the impregnation is removed by washing. |
| future state change | Since there are no gaps to fill, there is little room for later impregnation. | Fischer remains and can be filled at any time |
The second line is decisive.previous chapterAs we saw in , if an impregnated emerald is cleaned, a "No Indications" certificate can be issued. LMHC itself has a special notes option for emeralds that are heavily washed and have a lot of fissures.
On the other hand,"None" cannot be created by washing.The oil can be washed away, but the cracks themselves will not go away. "None" can be said to be an extremely difficult rating to create manually later.
The third line is also important in practice. "None" stones do not have enough gaps to fill, so the contents of the identification report are unlikely to change in the future.The identification report only tells about the condition at the time of inspection.This principle also applies to "None," but the amount of risk associated with that principle is clearly different between the two.
In SELBY
For these reasons, SELBY does not lump "None" and "No Indications" together as the same "non-oil." Both evaluations should be respected, but the difference in the nature of the material, such as the presence or absence of cracks, affects both the durability and the stability of the condition in the future. At purchasing and sales sites, we always distinguish and check which word is in the TREATMENT column of the identification book.
The gray area of “oil removal”
If an impregnated emerald is washed to remove the oil and sent for identification in that condition, a certificate of "No Indications of Clarity Enhancement" could theoretically be issued. This is not illegal or fraudulent, but if a consumer buys a stone imagining that it has never been filled with oil, there will be a gap between expectations.
LMHC's consideration of this situation can be seen in the design of Information Sheet #5. The same sheet isEmeralds that are heavily washed and have many fissures visible to the naked eye.We provide an option to add a special note to your report that mentions those phishers. Additionally, opaque oil/resin residues left inside the fisher after cleaning or due to deterioration are not subject to reporting under the framework of this sheet, but a note may be added to the effect that ``residues are present'' as necessary.If you see a "No Indications" stone with a lot of fishers, it's worth reading the notes in the report.
Still, the basis of price is color
Finally, to avoid misunderstandings, I would like to add: So far I have explained the difference between "None" and "No Indications",The degree of impregnation is only part of the value equation.GIA itself states in a 1999 paper that impregnating cannot change the natural color of a stone, and dull stones will remain dull even after impregnation.
The ``20-30%'' of SELBY mentioned above is alsoComparison assuming the same level of color, size, and internal conditionIt is. There are usually situations in which "F1", which has excellent color, is rated higher than "None", which has inferior color. The information that it is oil-free is only a yardstick when comparing stones that have the same conditions, and is not an indicator by itself to determine value.
What to check when reading the identification book
When considering a used specimen, please note the following regarding the certificate of authenticity.
- Publication date. Since impregnation is reversible, "No Indications" from 10 or 20 years ago do not guarantee the current state. Stones set in jewelry that has been worn for a long time may have filler that dries out over time, or may be affected by heat or chemicals during repairs. On the other hand, there is a possibility that the item may have been coated with oil for aesthetic purposes after purchase.
- Is it loose or set in the product?. GIA's Clarity Enhancement Classification Report has, since its inception, only covered loose natural emeralds, with a separate standard identification report issued for mounted stones with a description of whether or not they have been treated.
- Is it the expression on the sales page or the description in the report?. Many of the products that claim to be ``oil-free'' have ``No Indications of Clarity Enhancement'' instead of ``None'' in their reports. If "None" is written, please check the original document to see if it is actually written in the TREATMENT section of the report, or if it is an original expression used by the seller to mean "no treatment."
Points to note when purchasing and selling
When purchasing, please check the following four points: original text, date of publication, laboratory, and whether it is loose or not. When selling, we recommend that you consult in advance to determine whether re-obtaining the certificate of authenticity is worth the price.
Checklist when purchasing
| Check items | things to see | reason |
|---|---|---|
| Original text of notation | Is the English text in the report “None” or “No Indications of Clarity Enhancement”? | The distinction between the two tends to be lost in Japanese translations of sales pages. |
| Publication date | When was the identification book inspected? | Because impregnation is reversible and the report only shows the condition at the time of inspection |
| Publishing lab | Is it an LMHC member lab or a lab that follows its own standards? | Due to the different degrees of uniformity of terminology and standards |
| Loose or product? | Was it loose when the report was published? | GIA's enhancement classification has been targeting loose natural emeralds. |
| Notes/Comments column | Reference to Fisher, presence or absence of residue notes | Because information suggesting “cleaned” may be placed |
| Color and internal state | Bright colors and inclusions with the naked eye and with a loupe | Color is the foundation of value. Because oil-free is only an additional point |
Handling precautions
LMHC recommends that special care be taken when repairing jewelry set with oil/resin-impregnated emeralds, as oil/resin fillers can be unstable to high temperatures and chemicals, and that the stone be removed before repair.
This caution is for stones F1 to F3,Even if it is a "No Indications" stone, the fisher itself still exists.If there are cracks, avoid using ultrasonic cleaners, steamers, sudden temperature changes, or strong shocks. The idea that "it's durable because it's oil-free" doesn't hold true. Rather, since the cracks are not filled with filling, care must be taken when handling them.
What you need to know when selling
If the certificate of authenticity is old, the condition of the item will take precedence in the purchase appraisal. Even if you purchase a stone without oil, if there are traces of impregnation at the time of appraisal, you will have no choice but to make a judgment based on that evaluation. On the other hand, even without a certificate of identification, a stone in good condition and with an excellent color will be valued accordingly. When considering re-obtaining a certificate of identification, please consult us in advance about the cost and expected difference in evaluation.
Frequently asked questions (FAQ)
Q1. Which is higher, "None" or "No Indications of Clarity Enhancement"?
It's not a hierarchical relationship. The two are different categories that can be used depending on whether or not phishers reaching the surface are observed. LMHC's Information Sheet #5 specifies that "None" should only be used when no phishers are observed, and "No indications of clarity enhancement" should be used only when phishers are observed. Neither showed clear signs of clarity enhancement. However, GIA states that most emeralds contain features that reach the surface, and stones that fall under None are exceptional.
Q2. If "No Indications", is the oil completely zero?
Not guaranteed.The classification chart printed on GIA's emerald report defines the stone condition that corresponds to this designation as "NO OR INSIGNIFICANT CLARITY ENHANCEMENT."GIA also stated in a 1999 research paper that even if a very small amount of foreign matter is detected, if it is determined that it does not significantly affect the appearance, it can be said that "no evidence of filling processing was detected." It is accurate to understand that it is not a test that proves zero at the molecular level.
Q3. Is "No Oil" written on the GIA identification report?
there is no. "Non-oil" and "No Oil" are names used by the distribution side, and are not terms used by identification organizations. The standard terminology used by LMHC member laboratories is "None," "No fissure filling," and "No indications of clarity enhancement/modification." If you see "No Oil" on the sales page, this is not a quotation from the report, but an expression from the seller, so please be sure to check the English text of the original report.
Q4. Does "None" mean high transparency and low inclusions?
no. GIA's Clarity Enhancement classification only evaluates filled surface-reaching fissures, not the clarity grade of the entire stone. GIA specifies that inclusions that do not reach the surface (crystalline or fluid inclusions) cannot be filled and are therefore not considered for this classification. Therefore, even if it is "None", there may be stones with many inclusions inside.
Q5. What are F1, F2, and F3?
A symbol that quantifies the degree of clarity enhancement. According to the GIA official FAQ, F1 means minor, F2 means moderate, and F3 means significant. GIA describes "minor" as meaning that the treatment has only a slight effect on frontal appearance, and "significant" as having a noticeable effect on appearance.
Q6. Can I think of F1 as “almost unprocessed”?
F1 is a stone that has been impregnated. It is not unprocessed. However, a 1999 GIA paper states that even if a large Fisher is present, if there is only a small amount of foreign material present, it will be classified as F1. In other words, F1 does not necessarily mean ``small Fisher'', but rather ``the effect of filling on appearance is small.'' This difference is important when considering durability.
Q7. If the identification card says "None", is it still oil-free?
"None" indicates that no fissure was observed, so as there are no gaps to fill, it can be said that the possibility of subsequent impregnation is theoretically low. However, the condition may change if the cut is reworked or damaged after the report is issued. In any case, the identification report describes the condition at the time of the inspection, and the LMHC also stipulates that it is possible to add a note to the report saying, ``This report only describes the condition at the time of the inspection.''
Q8. If I take it in for identification after draining the oil, will it show "No Indications"?
In theory, it is possible to state "No Indications of Clarity Enhancement" if cleaning results in no traces of filling that would affect the appearance. LMHC anticipates this situation and provides an option for emeralds that are heavily washed and have a large number of visible phisers to add a disclaimer mentioning those phisers. Additionally, it is possible to place a note to the effect that ``residue exists'' regarding opaque residue left after cleaning. For stones with "No Indications" that have many fishers, it is worth reading the notes section.
Q9. I saw the symbols C1, C2, and C3. Is it different from F scale?
It's a different classification. LMHC's Information Sheet #5 specifies C1 (small amount), C2 (medium amount), and C3 (large amount) as classifications for filling resin/wax into wide cracks or cavities (deficiency), in addition to filling into fissures (F1 to F3). Please do not confuse the two as they are evaluated differently.
Q10. What are "Filler Type: A" and "Filler Type: B"?
These are the results of optional filler type identification provided by GIA starting December 15, 2024. According to the official GIA press release (dated December 11, 2024), if fillers are present, the report will indicate one of the following conclusions: Filler Type: A (can contain oils, waxes, and natural resins), Filler Type: B (man-made resins), or Clarity Enhancement Material not currently identified. Please note that GIA identifies the type of filler, not the product name.
Q11. How is it written if colored oil is used?
LMHC's Information Sheet #5 separates emeralds filled with fissures or fractures with color-affecting colorants, with a statement to the effect of ``Coloured filler in fissures/fractures'' or ``indications of clarity and color enhancement/modification by colorants.'' The handling is different from filling with colorless to almost colorless oil/resin.
Q12. Is the notation the same for laboratories other than GIA?
LMHC member laboratories are working to unify terminology. Names listed in the rights statement in Information Sheet #5 are Central Gem Laboratory (CGL/Japan), CISGEM (Italy), DSEF German Gem Lab (Germany), GIA Laboratory (USA), GIT (Thailand), Gübelin Gem Lab (Switzerland), and SSEF (Switzerland). Labs other than these may use their own wording, so please check the definitions for each report.
Q13. Is it okay to use ultrasonic cleaning for oil-free emeralds?
Not recommended. Fisher is present in the "No Indications" stone. If there are cracks, avoid using ultrasonic cleaners, steamers, sudden temperature changes, or strong impacts. LMHC also recommends removing stones when repairing jewelry, as oil/resin fillers can be unstable to high temperatures and chemicals. Oil-free does not mean high durability.
Q14. Will oil-free products always sell at a higher price?
no. In a 1999 paper, GIA clarified that "significant enhancement does not necessarily mean low value, and minor enhancement or no evidence does not necessarily mean high value." The degree of impregnation is only one part of the value equation; color and weight, as well as the amount of internal inclusions that don't reach the surface, play a major role. Oil-free is a significant additional factor when comparing stones of the same level of color and internal condition.
Q15. When buying a used car, how far should I look in the certificate of authenticity?
At a minimum, please check the following five points: (1) the original English text (None or No Indications, F1 to F3), (2) publication date, (3) publication lab, (4) whether it was loose at the time of publication, and (5) comments/notes. The publication date is especially important. This is because impregnation is a reversible process that can be removed and reapplied, and the report describes the condition at the time of inspection. If you are unsure, we can look at the actual product and explain.
Q16. If both are oil-free, are the prices the same for "None" and "No Indications"?
It's not the same.Examples of what SELBY has handled so far and what we have experienced at purchasing and sales sitesIf the color, origin, size, and internal condition are at the same level, an individual with a GIA "None" rating may be valued 20 to 30% higher than an individual with a "No Indications" rating. The main reasons are: (1) There are no cracks, so the durability assumptions are different, and (2)``No Indications'' can be theoretically obtained by removing impregnation by cleaning, but ``None'' cannot be created by cleaning.(Because the cracks do not disappear even after washing); and (3) There are no gaps to fill, so future changes in condition are less likely to occur. However, this is not a market price list, but is just SELBY's practical experience, and the price is based on color.
Summary
The difference between "None" and "No Indications of Clarity Enhancement" is not the amount of oil.Fisher presence or absenceIt is. As LMHC's Information Sheet #5 clearly states in a footnote, "None" is only used when no phishers are observed, and "No indications of clarity enhancement" is only used when phishers are observed. This correspondence can also be seen in the classification table printed on GIA's Emerald Report.
And "No Indications" means "No Indications" according to GIA's classification. or Insignificant” is included. This is not a complete zero guarantee, but rather a determination that ``no traces of filling that would affect the appearance were observed.'' Furthermore, impregnation is a reversible process, and the certificate only tells about the condition at the time of inspection.
And the evaluation in the market is also different between these two. Based on actual examples that SELBY has dealt with and experience in purchasing and sales sites, there are cases where "None" is rated 20-30% higher than "No Indications" if the conditions are the same. In the background,"No Indications" can be obtained by washing, but "None" cannot be created by washing.There is a definite asymmetry in that the cracks do not disappear even after washing.
Finally, I would like to leave you with GIA's own words. The degree of impregnation is only part of the value equation, and "significant" does not necessarily mean low value, and "minor" or "no evidence" does not necessarily mean high value. Choosing a stone based on just one thing: oil-free may distract you from the most valuable element, which is color.
Knowing the exact meaning of the notation is a tool for choosing a good stone, not a purpose. If you have any questions about the description of emeralds or how to read your identification book, please feel free to contact SELBY.
SELBY handles emeralds with GIA certificates.
▶ View oil-free emeralds with GIA certificate
You can view the actual loose pieces with the "None" and "No Indications" ratings explained in this article, along with the identification book.
Go to emerald product list
▶ Submit your emerald for appraisal
For those who are curious about how to read the identification book of their stone and its current evaluation. A buyer who specializes in determining authenticity and evaluating value will respond.
About purchase/assessment
Related articles
Reference materials
- Laboratory Manual Harmonization Committee (LMHC), Information Sheet #5: "Emerald – fissure filling / clarity enhancement," Version 6, May 2025.
https://www.lmhc-gemmology.org/information-sheets/ - McClure, S.F., Moses, T.M., Tannous, M., Koivula, J.I. (1999) "Classifying Emerald Clarity Enhancement at the GIA Gem Trade Laboratory," Gems & Gemology, Vol. 35, No. 4, pp. 176–185.
https://www.gia.edu/doc/Classifying-Emerald-Clarity-Enhancement-at-the-GIA-Gem-Trade-Laboratory.pdf - GIA, "On a Laboratory report for a treated emerald, what does F1, F2 and F3 mean?" (GIA official FAQ)
https://www.gia.edu/gia-faq-analysis-grading-treated-emerald-f1-f2-f3 - GIA official press release “GIA Enhances its Emerald Reports” (dated December 11, 2024 / filler type identification started December 15, 2024)
https://www.gia.edu/gia-news-press/gia-enhances-emerald-reports -
GIA Emerald Origin Report No. 5526246582 (published August 29, 2025)/ Included with Ruth handled by Selby Co., Ltd. Check the "CLARITY ENHANCEMENT" classification table printed on the report in person.
https://reportcheck.gia.edu/(Can be verified by report number) - Roskin Gem News Report “GIA Enhances its Emerald Reports: Filler Identification Now Available as an Option” (December 15, 2024)
https://roskingemnewsreport.com/gia-enhances-its-emerald-reports-filler-identification-now-available-as-an-option/ - Johnson, M.L., Elen, S., Muhlmeister, S. (1999) "On the Identification of Various Emerald Filling Substances," Gems & Gemology, Vol. 35, No. 2, pp. 82–107.
- Appraisal and sales practices of Selby Co., Ltd. (loose purchasing and handling knowledge in the second-hand market)
*The content of this article is based on information as of July 2026. The terminology and service content of classification organizations may be revised, so please check the official announcements of each organization for the latest information.