Aluminite
Mineral Al2(SO4)(OH)4·7H2O
Also called Websterite
About it
Chalk-white, soft, earthy nodules found in clays and in weathered rock rich in pyrite. First described from Halle in Germany; also known from Newhaven in England.
- Type
- Mineral
- Group
- Sulfate, hydrated
- Formula
- Al2(SO4)(OH)4·7H2O
- Hardness (Mohs)
- 1–2
- Specific gravity
- 1.66–1.82
- Streak
- white
- Lustre
- earthy, dull
- Crystal system
- Monoclinic
- Colours
- white, greyish white
- Transparency
- opaque
- Cleavage and fracture
- none; earthy fracture
Typical values: real specimens vary. For more, see mindat.org.