Hardystonite
Mineral Ca2ZnSi2O7
About it
A plain white to grey granular mineral that glows violet-blue under shortwave UV; known almost only from Franklin, New Jersey.
- Type
- Mineral
- Group
- Silicate (sorosilicate), melilite group
- Formula
- Ca2ZnSi2O7
- Hardness (Mohs)
- 3–4
- Specific gravity
- 3.39–3.44
- Streak
- white
- Lustre
- vitreous (glassy), greasy
- Crystal system
- Tetragonal
- Colours
- white, grey, pinkish, light brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- distinct basal
- Under UV light
- violet-blue under shortwave UV
Typical values: real specimens vary. For more, see mindat.org.