Hackmanite
Variety Na8(Al6Si6O24)Cl2
Take care.
- Fades or changes in light: Keep it in the dark, out of sunlight and bright display lights.
About it
Sodalite that changes colour: it deepens to pink or violet after UV light and fades again in daylight (tenebrescence). Mont Saint-Hilaire, Quebec, Afghanistan, and Myanmar are known sources.
- Type
- Variety
- Group
- Sodalite variety
- Formula
- Na8(Al6Si6O24)Cl2
- Hardness (Mohs)
- 5.5–6
- Specific gravity
- 2.15–2.4
- Streak
- white
- Lustre
- vitreous (glassy), greasy
- Crystal system
- Isometric (cubic)
- Colours
- pink, violet, white, grey, green
- Transparency
- transparent, translucent
- Cleavage and fracture
- poor dodecahedral; uneven to conchoidal fracture
- Under UV light
- bright orange under longwave UV
Typical values: real specimens vary. For more, see mindat.org.