Sapphire
blue · Corundum family
| Also known as | Corundum (Corundum family) |
|---|---|
| Colour | Blue |
| Mohs hardness | 9.0 |
| Lustre | Vitreous |
| Streak | Colorless |
| Crystal system | Trigonal |
| Transparency | Transparent to nearly opaque |
| Cleavage | Poor |
| Fracture | Conchoidal, splintery |
| Chemical formula | Aluminium oxide, Al 2 O 3 |
| Specific gravity | 3.98–4.06 |
What is Sapphire?
Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al2O3) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros (σάπφειρος, itself from a Semitic origin), which referred to lapis lazuli. Sapphire with colors other than its typical blue is referred to as "fancy sapphire", and can be in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum st
How to identify Sapphire
- Lustre: Vitreous.
- Hardness: Mohs 9.0 — hard enough to scratch glass.
- Streak: Colorless.
- Habit: Trigonal crystal system.
Sapphire in different forms
Stones often confused with Sapphire
Frequently asked questions
How hard is Sapphire?
Sapphire is Mohs 9.0 on the hardness scale.
What colour is Sapphire?
Sapphire is typically blue (Typically blue, but varies).