Gmelinite
Mineral (Na2,Ca)Al2Si4O12·6H2O
Also called Gmelinite-Na and Gmelinite-Ca
About it
Six-sided tablets and pyramids, white to salmon pink, in basalt cavities; Nova Scotia's Bay of Fundy shore and County Antrim in Northern Ireland are classic localities.
- Type
- Mineral
- Group
- Silicate (tectosilicate), zeolite group
- Formula
- (Na2,Ca)Al2Si4O12·6H2O
- Hardness (Mohs)
- 4.5
- Specific gravity
- 2.03–2.17
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Hexagonal
- Colours
- colourless, white, pink, salmon, greenish
- Transparency
- transparent, translucent
- Cleavage and fracture
- good prismatic
Typical values: real specimens vary. For more, see mindat.org.