Pyrophyllite
Mineral Al2Si4O10(OH)2
Also called Agalmatolite
About it
Looks and feels like talc but often grows as radiating sprays of pearly blades; massive material is mined in North Carolina.
- Type
- Mineral
- Group
- Silicate (phyllosilicate), pyrophyllite group
- Formula
- Al2Si4O10(OH)2
- Hardness (Mohs)
- 1–2
- Specific gravity
- 2.65–2.9
- Streak
- white
- Lustre
- pearly, greasy, dull
- Crystal system
- Monoclinic
- Colours
- white, grey, pale green, yellow, brown
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- perfect in one direction, flexible but not elastic flakes
Typical values: real specimens vary. For more, see mindat.org.