Sphalerite
Mineral ZnS
Also called Blende, Zinc blende, Blackjack, Rosin jack, Ruby jack, and Cleiophane
About it
Resinous to adamantine with a pale streak and six cleavage directions; iron-rich black pieces look metallic. The main zinc ore; gemmy red and orange crystals come from the Picos de Europa, Spain, and Tennessee.
- Type
- Mineral
- Group
- Sulfide, sphalerite group
- Formula
- ZnS
- Hardness (Mohs)
- 3.5–4
- Specific gravity
- 3.9–4.1
- Streak
- white to yellow-brown
- Lustre
- adamantine (diamond-like), resinous, submetallic
- Crystal system
- Isometric (cubic)
- Colours
- yellow, brown, red, green, black, colourless
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- perfect dodecahedral, six directions
- Under UV light
- some glows orange or yellow under longwave UV
Typical values: real specimens vary. For more, see mindat.org.