YAG (yttrium aluminum garnet) is a man-made crystal used as an imitation of diamond. It is made in many colors, and the colorless crystal is cut as a diamond simulant.
Properties
| Refractive index | 1.833 |
|---|---|
| Birefringence | None (singly refractive) |
| Optic character | Singly refractive |
| Dispersion | 0.028 |
| Specific gravity | 4.55 |
| Hardness (Mohs) | 8.25 (8 1/4) |
| Crystal system | Cubic |
| Pleochroism | None |
| Absorption spectrum | Not recorded |
Published values. They change a little from stone to stone. Our tools do not model YAG yet. Sources: GIA · International Gem Society · Gemdat
In more detail
YAG is much less brilliant than diamond, and it lacks diamond's distinct fire and luster. It has good hardness and high clarity. Cubic zirconia later passed it and the other classic simulants in popularity. Today YAG is no longer much used as a diamond simulant.
Related terms
- Simulant: A simulant is a material that looks like a gem but has a different chemistry, structure and properties. Cubic zirconia, moissanite and glass are diamond simulants.
- GGG: GGG (gadolinium gallium garnet) is a man-made crystal used as an imitation of diamond. It is a close relative of YAG.
- Cubic zirconia: Cubic zirconia (CZ) is a man-made diamond simulant. GIA names it as the most common simulant today.
- Diamond: Diamond is a single element, carbon, with every atom bonded to four neighbors in a cubic crystal. It is the hardest gem, Mohs 10.
- Brilliance: Brilliance is the white light that a cut stone returns to the viewer. In our census, it is the share of entering light that leaves through the crown toward the viewer.