Microcline
Mineral KAlSi3O8
Also called Amazonstone and Perthite
About it
The common pink or white potassium feldspar of pegmatites, where crystals can reach metres. Blue-green amazonite with smoky quartz from Pikes Peak, Colorado, is a classic pairing.
- Type
- Mineral
- Group
- Silicate (tectosilicate), feldspar group
- Formula
- KAlSi3O8
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 2.54–2.57
- Streak
- white
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Triclinic
- Colours
- white, pink, salmon, cream, blue-green, green, grey
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect and good in two directions at nearly 90°
Typical values: real specimens vary. For more, see mindat.org.