Topaz
| Colour | Blue, Yellow, Clear, White, Brown |
|---|---|
| Mohs hardness | 8 (defining mineral) |
| Lustre | Vitreous |
| Streak | Grayish White |
| Crystal system | Orthorhombic |
| Transparency | Transparent |
| Cleavage | [001] Perfect |
| Fracture | Subconchoidal to uneven |
| Specific gravity | 3.49–3.57 |
What is Topaz?
Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al2SiO4(F, OH)2. It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden-brown to yellow-orange. Topaz is often treated with heat or radiation to make it a deep blue, reddish-orange, pale green, pink, or purple.
How to identify Topaz
- Lustre: Vitreous.
- Hardness: Mohs 8 (defining mineral) — hard enough to scratch glass.
- Streak: Grayish White.
- Habit: Orthorhombic crystal system.
Topaz in different forms
Stones often confused with Topaz
Frequently asked questions
How hard is Topaz?
Topaz is Mohs 8 (defining mineral) on the hardness scale.
What colour is Topaz?
Topaz is typically blue, yellow, clear, white, brown (Colorless (if impurities are absent), white, blue, brown, orange, gray, yellow, yellowish brown, green, pink, reddish pi).