Formula: Zn7(CO3)2(OH)10
Anhydrous carbonate containing hydroxyl
Crystal System: Monoclinic
Specific gravity: 3.51 measured, 3.55 calculated
Hardness: 3 to 4
Streak: White
Colour: Colourless, light grey in aggregates

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).
A specimen has been found where the exposed surface 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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