Laboratory Disclosure Comments for Colored Gemstones

Ruby and Sapphire heat treatment terminology*:

Condition No indication of heating Indication of heating with minor modifications (no residues) Indication of heating (no residues) Indication of heating with residue in fissures
Report Alpha numeric NTE MTE TE TE1 TE2 TE3 TE4 TE5
Report Text No indication of heating Indication of heating at moderate temperature Indication of heating Minor residue in fissures Minor residue in fissures Significant residue in fissures
TE = Thermal enhancement
NTE = No thermal enhancement
No indication of heat treatment: NTE
Indication of heat treatment: TE
Indication of heat treatment: TE1, TE2, TE3, TE4 and TE5
Indication of heat treatment: C1, C2 and C3
Variation when both fissures and cavities contain glass:
Condition Indication of heating with residue in cavities
Report Alpha numeric C1 C2 C3
Report Text Minor residue in cavities Moderate residue in cavities Significant residue in cavities

Variation when both fissures and cavities contain glass:
Indication of heat treatment width residue in fissures and cavities: TE2, C1 or C2, ...

TE: Indication of heating:
Basic heat treatment, with no residue detected within cavities and/or fissures of the ruby or sapphire.

MTE: Indication of heating:
Traditional heat treatment at moderate temperature, without the use of flux, not altering the inclusions, only bringing to the stone (ruby or sapphire) an enhancement of the color. This treatment is only detectable by infrared spectrometry.

(HPHT): Indication of HPHT treatment:
Rubies and sapphires that have been subjected to high-pressure-high-temperature treatment are described as such.

(Lead/Bismuth): Indication of lead or bismuth-rich glass in fissures:
Vitreous residue was encountered with indication of lead glass/bismuth glass in fissures.

Assembled ruby:
When the edges of cracks do not coincide each other and that the integrity of the stone is only due to the presence of the vitreous substance that holds the pieces together, usually by lead-rich glass. Indication of lead or bismuth-rich glass in fissures: Vitreous residue was encountered with indication of lead glass/bismuth glass in fissures.

(SD): Surface diffusion:
The corundum's color has been altered via a surface diffusion process; whereby coloring elements have been allowed to penetrate the stone to a minute depth. While this artificial color is stable, it may be removed during any subsequent re-cutting and/or re-polishing, except for the titanium deep diffusion.

(Light elements): Light elements diffusion:
The item's color has been subtly or significantly modified via a bulk diffusion process, whereby beryllium has been penetrated through the stone. This color is stable. Detection using LIBS causes near-undetectable marks at the stone surface (on the girdle). This test will be applied on Ruby and Sapphire, for yellow, orange, orange-red and green tint, but also on blue sapphire suspected of having been too dark in color, and lightened by a multi-step process involving the diffusion of light elements.

Fade test:
For yellow and orange sapphire, sapphire with combinations of yellow or orange and orange-red ruby, a fade test may be carried out to determine its color stability. This test can indicate irradiation treatment in particular gemstones. Only with the customer's written permission.

A- Jade: No indication of enhancement beyond traditional and basic room temperature waxing (during the polishing process).
B- Jade: Indication of bleaching and subsequent polymer impregnation.
C- Jade: Indication of dying, after bleaching and subsequent oil or polymer impregnation.
C-Jade (variation): Indication of dying without detectable oil or polymer.

Clarity enhancement may be classified as "minor'', "moderate", "medium", "significant" or "very significant", depending on the amount of filling substances detected within the tested item's surface-reaching fissures and/or cavities.

Identification of oil and/or resin is systematically carried out. It is not mentioned in the report only at the written request of the customer.

Some of the following treatments may not be detected with sufficient reliability by current gemological tests. In this case, the presence or absence of these treatments will not be specified in our report.

- Heated or irradiated stones that are frequently accepted in the trade:
Spodumene, beryl, zoisite (tanzanite), tourmaline, topaz, zircon, quartz.
- Paraiba-type tourmalines are usually heated.
- Stones that are commonly chemically treated:

Dyed chalcedony, jadeite of other colors than green.