Polyhalite
Mineral K2Ca2Mg(SO4)4·2H2O
Take care.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
About it
Brick-red to salmon fibrous masses in potash and salt deposits, coloured by tiny flakes of hematite. Mined as fertilizer in North Yorkshire and found at Carlsbad, New Mexico.
- Type
- Mineral
- Group
- Sulfate, hydrated
- Formula
- K2Ca2Mg(SO4)4·2H2O
- Hardness (Mohs)
- 2.5–3.5
- Specific gravity
- 2.77–2.78
- Streak
- white
- Lustre
- vitreous (glassy), silky, resinous
- Crystal system
- Triclinic
- Colours
- brick red, salmon pink, white, grey, colourless
- Transparency
- translucent, opaque
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.