Sclarite

Formula: Zn7(CO3)2(OH)10
Anhydrous carbonate containing hydroxyl
Specific gravity: 3.51
Hardness: 3 to 4
Streak: White
Colour: Colourless, light grey in aggregates
Environments:

Hydrothermal environments

Sclarite is a very rare secondary zinc carbonate, known mainly from a single specimen from the type locality, the Franklin Mine, Franklin, Sussex county, New Jersey, USA. The sclarite occurs as tiny bladed crystals or spherules in veinlets in willemite - franklinite ore without calcite, possibly of hydrothermal origin, from a metamorphosed stratiform zinc orebody (Webmin, Mindat).
Associated minerals here include secondary zincite, willemite, franklinite, rhodochrosite, leucophoenicite, gageite and chlorophoenicite (Mindat, HOM, Dana).
The exposed surface of the specimen is coated unevenly with sparse leucophoenicite and dense, abundant, microcrystalline, fibrous coatings of gageite and sparse secondary zincite. Upon these minerals are l mm spherules of rhodochrosite, additional gageite and chlorophoenicite; these are coated,in turn, and unevenly, with very sparse sclarite, which is intimately associated with secondary zincite and an unnamed, zinc-magnesium carbonate mineral. Willemite is present throughout this secondary assemblage, occurring as a fine dust-like dispersal of microcrystallites (AM 74.1355-1359).

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