Grossular
greenyelloworange · Garnet family
| Also known as | Garnet (Garnet family) |
|---|---|
| Colour | Green, Yellow, Orange |
| Mohs hardness | 6.5 to 7 |
| Lustre | greasy to vitreous |
| Streak | Brown |
| Crystal system | Cubic |
| Transparency | Can form with any diaphaneity, translucent is common |
| Cleavage | none |
| Fracture | conchoidal to uneven |
| Chemical formula | Ca 3 Al 2 (SiO 4 ) 3 |
| Specific gravity | 3.61 (+.15/−.04) |
What is Grossular?
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, grossularia, in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone.
How to identify Grossular
- Lustre: greasy to vitreous.
- Hardness: Mohs 6.5 to 7 — about as hard as a steel knife.
- Streak: Brown.
- Habit: Cubic crystal system.
Grossular in different forms
Stones often confused with Grossular
Frequently asked questions
How hard is Grossular?
Grossular is Mohs 6.5 to 7 on the hardness scale.
What colour is Grossular?
Grossular is typically green, yellow, orange (light to dark green, light to dark yellow to reddish brown, brown, orange, red, yellow, green, white, occasionally trans).