Grossular (Calcium Aluminum Garnet)
The name is derived from "grossularia" (gooseberry). Found in skarn and serpentine, it boasts the most diverse range of colors among all garnets.
A wide range from yellow-green to colorless and pink
Basic Information
| English Name | Grossular |
|---|---|
| Japanese Name | Kaiban Zakuro-ishi (Calcium Aluminum Garnet) |
| Chemical Formula | Ca3Al2(SiO4)3 |
| Hardness | 6.5–7 |
| Specific Gravity | Approx. 3.6 (varies by composition) |
Colors and Major Varieties
- Tsavorite: Bright green primarily colored by V (deep green colored primarily by Cr is difficult to classify as Tsavorite).
- Hessonite: Yellow to brown hues. Varieties with a strong reddish tint are called cinnamon stone.
- Rose Stone: Originating from marble matrices. Opaque to translucent pink hues (with deep purplish-black sections in the center).
Green colors are produced by a mix of Fe, Cr, and V, resulting in a wide spectrum from yellow-green to deep green.
Distribution, Treatment, and Similar Stones
Treatment: Fracture oiling/resin impregnation.
Similar Stones: Yellow to yellow-brown: Spessartine, Idocrase / Green: Cr Tourmaline, Cu Diopside, Demantoid (Andradite) / Blackish-green: Low-quality Emerald.
Related: Hydrogrossular (Hydrogrossularite) resembles Rose Stone after polishing.