Northupite
Mineral Na3Mg(CO3)2Cl
About it
Colourless to brownish octahedrons of sodium magnesium carbonate with chlorine, from the muds of salt lakes. Searles Lake, California, is the classic source; also found in Wyoming's Green River Formation.
- Type
- Mineral
- Group
- Carbonate (with chloride)
- Formula
- Na3Mg(CO3)2Cl
- Hardness (Mohs)
- 3.5–4
- Specific gravity
- 2.38
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Isometric (cubic)
- Colours
- colourless, white, grey, yellow, brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.