Natrolite
Mineral Na2Al2Si3O10·2H2O
About it
Slender, square-sided needles in radiating sprays in basalt and alkaline rocks; the white matrix of benitoite at California's Dallas Gem mine, and large crystals from Mont Saint-Hilaire, Quebec.
- Type
- Mineral
- Group
- Silicate (tectosilicate), zeolite group
- Formula
- Na2Al2Si3O10·2H2O
- Hardness (Mohs)
- 5–5.5
- Specific gravity
- 2.2–2.26
- Streak
- white
- Lustre
- vitreous (glassy), silky
- Crystal system
- Orthorhombic
- Colours
- colourless, white, grey, yellowish, pink
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect prismatic
Typical values: real specimens vary. For more, see mindat.org.