Humboldtine

humboldtine

tschermigite

cassiterite

tourmaline

Images

Formula: Fe2+(C2O4).2H2O
Organic compound, humboldtine group
Crystal System: Monoclinic
Specific gravity: 2.28 measured, 2.307 calculated
Hardness: 1½ to 2
Colour: Yellow to amber-yellow, lemon-yellow
Solubility: Soluble in acids
Environments

Pegmatites very rarely
Coal deposits
Hydrothermal environments

Humboldtine is a rare authigenic organic mineral occurring on fracture surfaces in coal deposits and rarely in granitic pegmatites and hydrothermal mineral deposits. It is a common biomineral formed by the action of lichens on iron-rich limestones and copper-bearing rocks (Mindat).
Humboldtine is associated with gypsum and tschermigite in coal seams, and with cassiterite, tourmaline and quartz in pegmatites and hydrothermal environments (HOM).

Localities

The type locality is the Korozluky magmatic rock occurrence, Korozluky, Most District, Ústí nad Labem Region, Czech Republic.

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