Kaolinite
Mineral Al2Si2O5(OH)4
Also called Kaolin and China clay
About it
Soft white clay that feels smooth and smells earthy when breathed on, formed where feldspar weathers; mined for porcelain in Cornwall and Georgia, USA.
- Type
- Mineral
- Group
- Silicate (phyllosilicate), kaolinite group
- Formula
- Al2Si2O5(OH)4
- Hardness (Mohs)
- 2–2.5
- Specific gravity
- 2.61–2.68
- Streak
- white
- Lustre
- earthy, dull, pearly
- Crystal system
- Triclinic
- Colours
- white, cream, grey, yellowish, pinkish
- Transparency
- opaque
- Cleavage and fracture
- perfect in one direction (microscopic)
Typical values: real specimens vary. For more, see mindat.org.