Gadolinium gallium garnet
Description
A colorless synthetic crystal of the garnet group that has been used as an imitation diamond. Gadolinium gallium garnet (GGG) stones are us. Cubic zirconia (CZ) are very hard and have a high refractive index. It is composed of a single crystal of synthetically prepared Zirconium oxide. During manufacture, calcium or yttrium are added as a metal oxide stabilizer, which allows the growth of the single crystal. The technique was first researched in France in the 1960s, then perfected in Russia in 1973 at the Lebedev Physical Institute. Commercial imitation diamonds have been on the market since 1976. Some coatings have been applied in recent years that make the stone visually indistinguishable from diamonds. The variations between the two stones are: 1) CZ are flawless, unlike natural diamonds, and 2) CZ has a lower thermal conductivity, higher dispersion, higher specific gravity, and often a poorer faceted cut.
Synonyms and Related Terms
GGG
Physical and Chemical Properties
- Luster = vitreous to subadamantine
- Pleochroism = none
- Fluorescence = moderate to strong pinkish orange in SW; inert to moderate orange in LW
- Birefringence = none
| Mohs Hardness | 6.5 - 7.5 |
|---|---|
| Density | 7.08 g/ml |
| Refractive Index | 1.970 |
| Dispersion | 0.045 (moderate fire) |
Comparisons
Properties of Natural and Simulated Diamonds
Resources and Citations=
- Gem Identification Lab Manual, Gemological Institute of America, 2016.
- Wikipedia: [1] (Accessed Dec 2022)
Gadolinium_gallium_garnet