Ilesite

ilesite

chvaleticeite

copiapite

rozenite

Images

Formula: Mn2+(SO4).4H2O
Hydrated manganese sulphate, rozenite group
Crystal system: Monoclinic
Specific gravity: 2.25 measured on artificial material, 2.26 calculated
Hardness: 2 to 3
Colour: Green, becoming white through dehydration
Solubility: Very readily soluble even in cold water. The aqueous solution effervesces with sodium carbonate and reddens blue litmus paper.
Environments

Hydrothermal environments

Ilesite is a rare secondary mineral in the oxidised zones of sulphide deposits (HOM). It may dehydrate to szmikite and may itself be a dehydration product of jôkokuite (Mindat).

Localities

At Chvaletice, Pardubice District, Pardubice Region, Czech Republic, ilesite is associated with rozenite, epsomite, copiapite, gypsum, melanterite and chvaleticeite (HOM).
Ilesite from Chvaletice - Image

At the type locality, the McDonnell claim, Hall Valley, Montezuma Mining District, Park County, Colorado, USA, ilesite occurs as loosely adhering, very friable, thick prisms, frequently terminated by truncated pyramids. Associated minerals include galena, pyrite, quartz, sphalerite and willemite (Mindat).

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