The American Gem Trade Association's

GEMSTONE
ENHANCEMENT
MANUAL

Industry Information Guides for:
Natural Gemstones and Man-Made Stones
Including Care and Handling Recommendations

Table of Contents

Natural Gemstones
INTRODUCTION I
PURPOSE
DEFINITIONS
Symbols for specific forms of enhancement
Designations: enhancement frequency; stability; care
Introduction to the gemstone enhancement charts
GEMSTONE ENHANCEMENT INFORMATION CHARTS
MAN-MADE MATERIALS
TAG CODES AND DEFINITIONS
Synthetic Materials
Imitation Products (Simulants)
Assembled Materials (Composite)

6.1 Edition
June, 1997
Printed in the U.S.A.
© American Gem Trade Association (AGTA)

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Disclosure Requirements for Natural Gemstones
Introduction I

This manual sets forth proper methods to comply with the FTC Guides. With the exception of the normal fashioning (cutting and polishing) of a diamond and other gemstones, it is the seller's responsibility at the time of sale to provide all informations pertinent to the enhancement of a natural gemstone. If the stone is man-made, it is also the seller's responsibility to disclose that fact. This information is required by the Federal Trade Commission (FTC).

Such information is required at each and all levels of jewelry commerce. Those specifically responsible to inform buyers include suppliers of uncut or polished diamonds and other gemstones; manufacturers and wholesalers of jewelry containing natural or man-made stones; retailers, including sales, over the counter, catalog, catalog showrooms, mail order firms, television or other media sales programs, and advertisers.

Anyone who is uncertain about these requirements may write the American Gem Trade Association, PO Box 420643, Dallas, TX 75342-0643.

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Definitions

ENHANCEMENT: Any treatment process other than cutting and polishing that improves the appearance (color/clarity/phenomena), durability, or availability of a gemstone.

All gemstones can be divided into three basic categories.

1. Those which are not enhanced.

• N   The "N" symbol appears on the chart only for natural stones which are not currently known to be enhanced (Alexandrite, Garnet, etc.), however, the "N" symbol can also be used for other stones in the event that a stone has received no enhancement and the seller will provide a guarantee that there has been none. That gemstone must be accompanied by a commercial document such as, an invoice, memorandum, and/or a laboratory report to support the fact the gemstone is not enhanced.

2. Those which are normally enhanced.

• E   The "E" symbol indicates that the gemstone is routinely enhanced. The type of enhancement covered by this symbol is indicated on the following charts.. For example: The "E" designation for Aquamarine means only the treatment that is described in the chart below, i.e. heat treatment. In the case of Emerald, the "E" designation only refers to the penetration of colorless oil, wax, natural or unhardened synthetic resins into voids.
   
  Since many enhancements are difficult or impractical to prove definitively, the approach taken in this manual is, unless otherwise indicated, to assume that such enhancement has been done to that particular gemstone. This assumption has been made in order to protect both the seller and the consumer.
   
  The "E" symbol may be used for those gemstones and for those enhancements as prescribed on the chart. However, if the method of enhancement is known, the seller should use the specific enhancement code in place of the "E" symbol.

3. Those which are treated in a non-traditional manner.

Those gemstones and enhancements not covered under the "N" & "E" symbols are addressed in a specific manner, as shown below.

• For example, Ruby "I". The surface cavities are filled with a foreign matter such as glass. Within the industry, this gemstone must be labeled with the letter "I." This information must also be provided to the consuming public in writing. Abbreviations and codes are not sufficient.

Note: Multiple Enhancement Techniques are sometimes applied to the same material. The most significant process should be listed first. All treatments must be listed.

Example: Diamond "FL" (Filling and Lasering.)

B	Bleaching:	The use of chemicals or other agents to lighten or remove a gemstone's color.
C	Coating:	The use of such surface enhancements as lacquering, enameling, inking, foiling, or sputtering of films to improve appearance, provide color or add other special effects.
D	Dyeing:	The introduction of coloring matter into a gemstone to give it new color, intensify present color or improve color uniformity.
F	Filling:	As a by-product of heat enhancement, the presence of solidified borax or similar colorless substances which are visable under properly illuminated 10X magnification.
G	Gamma/Electron Irradiation:	The use of gamma and/or electron bombardment to alter a gemstone's color; may be followed by a heating process.
H	Heating:	The use of heat to effect desired alteration of color, clarity, and/or phenomena. (Residue of foreign substance in open fractures is not visable under properly illuminated 10X magnification.)
I*	Infilling:	The intentional filling of surface breaking cavities or fractures usually with glass, plastic, opticon with hardeners and/or other hardened foreign substances to improve durability, appearance and/or add weight.
L	Lasering:	The use of a laser and chemicals to reach and alter inclusion in diamond.
O	Oiling/Resin Infusioin:	The intentional filling of surface breaking cavities of a colorless oil, wax, natural resin, or unhardened man-made material into fissured transparent/translucent gemstones to improve appearance. (i.e., oil, man-made resin, cedar wood oil, Canadian balsam, paraffin, etc.)
R	Irradiation:	The use of neutron, requiring an environmental safety release from the Nuclear Regulator Commission (NRC), with the combination of any other bombardment and/or heat treatment to alter a gemstone's color.
S*	Bonding:	The use of colorless bonding agent (commonly plastic) within a porous gemstone to give it durability and improve appearance.
U	Diffusion:	The use of chemicals in conjunction with high temperatures to produce color and/or asterism-producing inclusions.
		Note: AGTA has adopted a resolution establishing AGTA's position regarding disclosure language which must be used by AGTA members in the sale of diffusion treated gemstones.
		It is an unfair trade practice to use the word "sapphire" or other names of gemstones in advertising, promotional literature, or commercial documents as descriptive of a diffused gemstone unless such word is immediately followed with equal prominence by the following statement:
		"(Gemstone): chemically colored (Colored) by diffusion" Example: "Sapphire: chemically colored blue by diffusion"
		If the color of the diffused gemstone does not permeate the entire stone, then the following statement must also appear:
		"Although the color induced in diffusion treated gemstones is permanent, it does not permeate the entire gemstone; therefore, recutting or repolishing is not recommended."
		The above disclosure language must be printed in a type size and location so as to be conspicuous.
W*	Waxing/Oiling:	The impregnation of a colorless wax, paraffin and oil in porous opaque gemstones to improve appearance.
	* New Code

Designations
Designations are based on a consensus of opinion rather than any available documentation.

A. Enhancement Frequency Designations

1. Rarely
2. Occasionally
3. Commonly
4. Usually
5. Always
6. Unknown

B. Enhancement Stability Designations

1. Excellent
2. Very Good
3. Good
4. Fair
5. Poor
6. Variable

C. Care Designation

1. Normal
2. Special
3. Extra Special

• The column labeled FREQUENCY USED represents a reasonable estimate of how commonly a particular enhancement process is utilized in the trade, based on information available at this time.
• The columns FREQUENCY USED and STABILITY refer specifically to the enhancement process applied to the material.
• The CARE REQUIRED and SPECIAL ADVISE columns reflect two basic concerns. The first relates to special care that may be necessary to preserve the enhancement applied to the material and the second issue addresses the need for any special care required by the specific gemstone variety, irrespective of enhancement.

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THE GEMSTONE ENHANCEMENT INFORMATION CHART

GEMSTONE	TAG CODE	ENHANCEMENT METHOD	FREQUENCY USED	STABILITY	CARE REQUIRED	SPECIAL ADVISE
Alexandrite	N	None	----	----	Normal
Amazonite	E or W   S	Impregnated with colorless wax, paraffin or oil to improve appearance Impregnated with plastic and other hardened agents to improve appearance	Usually   Occasionally	Good to Fair   Very Good	Special   Normal	Avoid heat, chemicals and ultrasonic
Amber	E or H   D	Heated to improve appearance, add "sun spangles" or deepen color Dyed or surface treated to add color	Occasionally   Rarely	Very good to good Variable	Special   Special	Avoid chemicals and ultrasonic Avoid repolishing surface, chemicals and ultrasonic
Amethyst	E or H	Heated to lighten color and/or to remove "smokey" components	Occasionally	Excellent	Special	Some unheated material may fade in long exposure to sun light
Ametrine	N	None	----	----	Normal
Ammolite	S	Impregnated with colorless hardened substances to increase stability	Commonly	Fair to Good	Special	Avoid heat, household chemicals and ultrasonic
Andalusite	N	None	----	----	Normal
Aquamarine	E or H	Heated to remove yellow components thereby producing a purer blue color	Usually	Excellent	Normal
Beryl
Blue     ("Maxixe Type")	G	Irradiated blue from pale pink or colorless	Always	Poor	Extra Special	Color fades, avoid light or heat
Pink	E or H	Heated to remove yellow component thereby producing a purer pink color	Commonly	Excellent	Normal
Yellow-Green	N	None	----	----	Normal
Red	N	None	----	----	Normal
Yellow	G	Produced by irradiation	Usually	Variable	Normal/Special depending on method	Certain stones may fade in light or heat

The "N" symbol may be used for any gemstone that the seller guarantees has not been enhanced. (see definition on page 75.)

The "E" symbol indicates a gemstone which is routinely enhanced. It can only be used for treatments for specific gemstones as pre- scribed on this chart. (See definition on page 75.)

All other tag codes are defined on pages 77 to 79 of this edition of the Gemstone Enhancement Manual.

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THE GEMSTONE ENHANCEMENT INFORMATION CHART CONT'D

GEMSTONE	TAG CODE	ENHANCEMENT METHOD	FREQUENCY USED	STABILITY	CARE REQUIRED	SPECIAL ADVISE
Chalcedony
Agate	E or D	Dyed	Usually	Good to Excellent	Normal
Black (Onyx)	E or D	Dyed	Always	Good to Excellent	Special	Certain stones may fade in light or heat
Banded	E or D	Dyed	Usually	Excellent	Normal
Blue	E or D	Dyed	Commonly	Fair to Good	Special	Certain stones may fade in light or heat
Green	E or D	Dyed	Usually	Fair to Good	Special	Certain stones may fade in light or heat
Carnelian	E or H D	Heated to produce color Dyed to produce color	Usually Occasionally	Excellent Good to Excellent	Normal Special	Certain stones may fade in light or heat
Jasper	D	Sometimes dyed to imitate other stones	Occasionally	Excellent	Normal
Chrysoprase	N	None	----	----	Normal
Chrysoberyl
Cat's Eye	G	Irradiated to improve asterism and color	Occasionally	Excellent	Normal
Transparent     Varieties
Yellow	N	None	----	----	Normal
Brown	N	None	----	----	Normal
Green

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