Witherite
Mineral BaCO3
Take care.
- Toxic: Wash your hands after handling it, don't lick or taste it, and don't make dust.
About it
Heavy, white, six-sided pyramid-like twins, much like aragonite but denser, and poisonous if swallowed. The Settlingstones and Fallowfield mines in northern England gave the classic crystals.
- Type
- Mineral
- Group
- Carbonate, aragonite group
- Formula
- BaCO3
- Hardness (Mohs)
- 3–3.5
- Specific gravity
- 4.27–4.29
- Streak
- white
- Lustre
- vitreous (glassy), resinous
- Crystal system
- Orthorhombic
- Colours
- colourless, white, grey, pale yellow
- Transparency
- transparent, translucent
- Cleavage and fracture
- distinct in one direction; uneven fracture
- Under UV light
- sometimes blue-white under UV
Typical values: real specimens vary. For more, see mindat.org.