Hackmanite
| Also known as | Sodalite (Sodalite family) |
|---|---|
| Colour | Pink, Purple |
| Mohs hardness | 5.5–6 |
| Lustre | Dull vitreous to greasy |
| Streak | White |
| Crystal system | Cubic |
| Transparency | Transparent to translucent |
| Cleavage | Poor on {110} |
| Fracture | Conchoidal to uneven |
| Specific gravity | 2.27–2.33 |
What is Hackmanite?
Sodalite is a tectosilicate mineral with the formula Na8(Al6Si6O24)Cl2, with royal blue varieties widely used as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite is a member of the sodalite group with hauyne, nosean, lazurite and tugtupite.
How to identify Hackmanite
- Lustre: Dull vitreous to greasy.
- Hardness: Mohs 5.5–6 — about as hard as a steel knife.
- Streak: White.
- Habit: Cubic crystal system.
Hackmanite in different forms
Stones often confused with Hackmanite
Frequently asked questions
How hard is Hackmanite?
Hackmanite is Mohs 5.5–6 on the hardness scale.
What colour is Hackmanite?
Hackmanite is typically pink, purple (Rich royal blue, green, yellow, violet, white veining common).