Dawsonite
Mineral NaAl(CO3)(OH)2
About it
White, silky sprays and tufts of fine needles in alkaline intrusions and some oil shales. Named for Canadian geologist J. W. Dawson; first found on the McGill University campus in Montreal, and fine at Mont Saint-Hilaire.
- Type
- Mineral
- Group
- Carbonate (with hydroxide)
- Formula
- NaAl(CO3)(OH)2
- Hardness (Mohs)
- 3
- Specific gravity
- 2.42–2.44
- Streak
- white
- Lustre
- vitreous (glassy), silky
- Crystal system
- Orthorhombic
- Colours
- white, colourless
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect prismatic
Typical values: real specimens vary. For more, see mindat.org.