Formula: Na2 Ca (CO3)2
Origin of name: for the Institute of the Earth's Crust (Russian: zemnoy kory = "earth's crust"), Russian Academy of Science, Siberian Branch where the mineral was first studied.
Crystal system: Hexagonal
Crystal class: 6mm of -6m2 or 6/m 2/m 2/m
Twinning:
Unit cell: a = 10.06, c = 12.72
Colour: Colourless
Diaphaneity: Transparent
Luster: Vitreous to pearly
Habit: Tabular grains with no faces, 0.1- 0.5 mm, radiating crystals, acicular
Hardness: 2
Specific gravity: 2.46
Cleavage: 1; Perfect parallel to tabular plane
Tenacity:
Streak: White
Synonyms/varieties:
Comments: Dimorphous with nyerereite, readily soluble in warm water
| Back to Alphabetical list | Colour photos | Optical properties/Thin sections | SEM images | TEM images | vibrational spectra description | IR spectra | Raman spectra | N-IR spectra | F-IR spectra | IES spectra |