Chemical Properties
Calcium manganite is a sulfate mineral containing calcium and sodium. Monoclinic crystal system, the crystals are plate-like or short columnar; the collective body is granular, scaly or reniform. Colorless, gray, white or light yellow. Streaks white. Glassy or waxy luster. Brittle. Hardness 2.5-3, density 2.75-2.85 g/cm3, slightly salty. Slowly soluble in water, decompose in water to produce fine needle-like gypsum crystals or mannite. Soluble in hydrochloric acid. The flame is yellow. Calcium manganite in contact with water from the glassy luster to earthy luster, the surface covered with a layer of "white frost". The mineral is widely distributed in the marine and lacustrine salt deposits, and with rock salt, argillite, gypsum, white sodium magnesium alum or heterohalite and other symbiotic. Calcium manganite is unstable under weathering conditions, and the secondary ones are made of hard gypsum with Na2SO4 solution.
Physical properties
Habit: tabular, prismatic.
Color: yellow, reddish gray, or red.
Luster: vitreous (glassy).
Diaphaneity: transparent to translucent.
Streak: white.
Fracture: brittle–conchoidal.
Cleavage: [001] perfect.
Occurrence: dry salt-lake beds in desert climates.
Definition
glauberite: A mineral consisting ofa mixed sulphate of sodium and calcium,Na
2SO
4.CaSO
4.
