Gemology School and Gem Laboratory - Asian Institute of Gemological Sciences

AIGS Laboratory Disclosure Comments for Colored Gemstones

Ruby and Sapphire

(New codes are effective as of 1 July 2021)

Effect of Heat Treatment	No Residue Found	Residue Within Fissures			Residue Within Cavities
Amount of Residue	None	Minor	Moderate	Significant	Minor	Moderate	Significant
AIGS Disclosure Code	"Indications of heating"	(minor)	(moderate)	(significant)	(1)	(2)	(3)

"Indications of heating" : Basic heat treatment, but with no residue detected within cavities and/or fissures. Rubies and sapphires that have been subjected to high-pressure, high-temperature (HPHT) treatment are usually also given this classification.

(Lead) / (Bismuth) : Lead and/or bismuth-rich, vitreous residue was encountered within the tested item’s fissures and/or cavities.

(SD) : The item’s color has been altered via a surface diffusion process, whereby coloring ions 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.

(Light Elements) : The item’s color has been subtly or significantly altered via a bulk diffusion process, where by beryllium has been penetrated through the stone. This color is stable. Detection using LIBS causes minor damages on the stone surface. This test will be applied on Rubies and Sapphires with orange tint and/or upon client’s request

(Fade test:) : For yellow and orange sapphires, and sapphires with combinations of yellow or orange, a fade test may be carried out to determine its color stability. This test can indicate irradiation treatment in particular gemstones.

Jadeite

A-Jade : No indication of enhancement beyond traditional and basic waxing.
B-Jade : Indication of bleaching and subsequent polymer impregnation.
C-Jade : Indication of dyeing.

Emerald

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

Identification of oil and/or resin is only carried out upon the client’s request, and charges may apply.

The following treatments are undetectable with current gemological tests. The presence or absence of these treatments will not be specified in our report.

- Heated or irradiated stones that are accepted in the trade:
Spodumene (Kunzite, Hiddenite), Beryl (Aquamarine, Morganite), Tanzanite, Tourmaline, Topaz, Zircon, Quartz.
- Chemically treated stones:
Dyed Chalcedony, Dyed Jadeite (of any color other than green), smoke or sugar treated Black Opal.