INTRODUCTION

GFCO GEM LAB® uses the term "NATURAL" to describe a gemstone originating from nature (in opposition to "SYNTHETIC" for man-made or imitation gemstones). The term "NATURAL" has no implication regarding the presence or not of a treatment, such being possibly disclosed as a comment on the main page or in the area featuring the testing methods. No explicit mention of absence of any treatment shall signify that the laboratory has not researched the presence or not of a treatment. In general, the laboratory does not check treatments for semi-precious gemstones (see point 5. thereafter). The comment regarding treatment for precious gemstones are as follows:


TREATMENT TERMS

1. Comments for rubies, sapphires and fancy sapphires (click to see details):

2. Comments for emeralds (click to see details):

3. Comments for jadeites (click to see details):

4. Comments for spinels (click to see details):

5. Comments for others stones (click to see details):

1. COMMENTS FOR RUBIES, SAPPHIRES AND FANCY SAPPHIRES


1.1. NO HEAT - NO TREATMENT

No treatment of any kind has been detected.

1.2. UNHEATED / NO HEAT

Applies only to unheated yellow sapphires (not tested for irradiation and impact).

1.3. STANDARD HEAT

Normal heat treatment which depending on the quantity of fissures, cracks and cavities present in the gem is to leave residues/filling commonly called borax, a type of glass. The chemical composition of borax may comprise some proportion of lead in some cases. This treatment is considered stable. No side/sub-comment shall signifiy no presence of residues/filling (see point 1.9. thereafter).

1.4. HEAT

Either a standard high temperature heat treatment or a high temperature heat treatment during which the adding of light element in order to improve/modify color cannot be excluded or a heat treatment combined with high pressure. These treatments are stable. LIBS testing should be used to validate or invalidate a light element heat.

1.5. FILLING HEAT

Heat treatment with the adding of lead glass. Caution must be taken when mounting/unmounting the gem as the glass will melt at a low temperature and may result in the gem to break. This treatment presents durability problems.

1.6. LIGHT ELEMENT HEAT

Microscope observation concludes to a high temperature heat treatment with the adding of light element in order to improve/modify color. LIBS testing is required in order to validate/invalidate such conclusion. This treatment is stable.

1.7. SURFACE DIFFUSION

High temperature heat treatment with the adding of a light element with purpose to improve/modify color but where the element only penetrates the gem near its surface. As a consequence, the gem is to lose color if recut or repolished several times.

1.8. FILLING HEAT & COLOR ENHANCEMENT

A coloring agent has been introduced in the lead glass. This treatment presents similar durability problems as described under 1.5.

1.9. APPENDIX TO COMMENT

The quantity of residues/filling subsequent to any heat treatment is to be mentioned by a below/side comment such as INSIGNIFICANT, MINOR, MODERATE, SIGNIFICANT or VERY SIGNIFICANT. The number (1) or (2) following the below/side comment signifies the following:

(1) = residues/filling limited to healed fissures and small fissures;
(2) = residues/filling in cracks and/or cavities and/or surface cavities and possibly healed fissures and small fissures.
No number shall mean it can be either (1) or (2).

NO SIDE/SUB-COMMENT SHALL SIGNIFY NO PRESENCE OF RESIDUES/FILLING. The quantification of filling is approximate and conducted by microscope observation.

2. COMMENTS FOR EMERALDS

Unless OIL is specified in the comment, the chemical composition of the element used to enhance clarity is not checked.

2.1. NO OIL - NO TREATMENT

The gem clarity has not been enhanced with any treatment.

2.2. INSIGNIFICANT

The gem contains almost no fissures so clarity enhancement is negligible.

2.3. MINOR

The gem clarity enhancement is standard representing the norm for the item in question.

2.4. MODERATE

The gem has been treated more than the norm, beyond MINOR level.

2.5. SIGNIFICANT

There is large presence of cavities filling with resin and materials.

3. COMMENTS FOR JADEITE

Bleach treatment is not tested and would require FTIR testing.

3.1. NO INDICATION OF COLOR ENHANCEMENT

The jade has not been dyed, color is natural.

3.2. DYED

The jade has been dyed, color is the result of a treatment.

4. TREATMENT COMMENTS FOR SPINELS


4.1. NO HEAT - NO TREATMENT

No treatment of any kind has been detected.

4.2. UNHEATED / NO HEAT

The gem has not been heated and no meaningful clarity enhancement by oil is worth being mentioned.

4.3. STANDARD HEAT

The gem has been heated. If any residues/filling, rules similar as for rubies apply (see 1.9.).

4.4. OIL

The gem clarity is enhanced by the presence of oil. The extra-comment MINOR, MODERATE or SIGNIFICANT is to be added for quantification.

5. COMMENT FOR OTHERS STONES


GFCO GEM LAB does not comment on treatments for semi-precious stones unless upon request. For all that a conclusion is reachable with a reasonable degree of certainty, it may comment on the absence of treatment or oppositely comment about the presence of a treatment. The following gemstones (list not exhaustive) are commonly - but not necessarily always - treated with heat or irradiation or both: blue topazes; some tourmalines, blue zircons, kunzites, blue apatites, aquamarine, quartzes and pearls (according to the United Stated Nuclear Regulatory Commission, gemstone irradiation treatment poses no risk to human health).

TESTING COMMENT

The methods used for testing and the results are indicated on the left page of the report. A special comment may feature in this area to inform about any elements of importance.