Haüyne
| Colour | Blue |
|---|---|
| Mohs hardness | 5 to 6 |
| Lustre | Vitreous to greasy |
| Streak | Very pale blue to white |
| Crystal system | Isometric |
| Transparency | Transparent to translucent |
| Cleavage | Distinct on {110} |
| Fracture | Uneven to conchoidal |
| Specific gravity | 2.4 to 2.5 |
What is Haüyne?
Hauyne or haüyne, also called hauynite or haüynite, old name Azure spar, is a rare tectosilicate sulfate mineral with endmember formula Na3Ca(Si3Al3)O12(SO4). As much as 5 wt % K2O may be present, and also H2O and Cl. It is a feldspathoid and a member of the sodalite group. Hauyne was first described in 1807 from samples discovered in Vesuvian lavas in Monte Somma, Italy, and was named in 1807 by Brunn-Neergard for the French crystallographer René Just Haüy (1743–1822). It is sometimes used as a gemstone.
How to identify Haüyne
- Lustre: Vitreous to greasy.
- Hardness: Mohs 5 to 6 — about as hard as a steel knife.
- Streak: Very pale blue to white.
- Habit: Isometric crystal system.
Haüyne in different forms
Stones often confused with Haüyne
Frequently asked questions
How hard is Haüyne?
Haüyne is Mohs 5 to 6 on the hardness scale.
What colour is Haüyne?
Haüyne is typically blue (Blue, white, gray, yellow, green, pink).