Hydromagnesite
Mineral Mg5(CO3)4(OH)2·4H2O
About it
White crusts, rosettes, and chalky masses in serpentinite and caves. It forms the white shores of Salda Lake, Turkey, and large mounds in playas near Atlin, British Columbia.
- Type
- Mineral
- Group
- Carbonate (with hydroxide)
- Formula
- Mg5(CO3)4(OH)2·4H2O
- Hardness (Mohs)
- 3.5
- Specific gravity
- 2.16–2.25
- Streak
- white
- Lustre
- vitreous (glassy), silky, pearly, earthy
- Crystal system
- Monoclinic
- Colours
- white, colourless
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- perfect in one direction
- Under UV light
- sometimes green or bluish white under UV
Typical values: real specimens vary. For more, see mindat.org.