Clinohedrite coating hardystonite, franklinite with willemite reaction rims. Franklin, New Jersey. Orange fluorescence under UV.
General
Category
Silicate mineral
Formula (repeating unit)
CaZn(SiO4)·H2O
IMA symbol
Cnh[1]
Strunz classification
9.AE.30
Dana classification
52.2.1.2
Crystal system
Monoclinic
Crystal class
Domatic (m) (same H-M symbol)
Space group
Cc
Unit cell
a = 5.09 Å, b = 15.82 Å, c = 5.38 Å; β = 103.39°; Z = 4
Identification
Color
Colorless to brown surface coating, clear to pale pink to amethystine crystals
Crystal habit
Thin to thick or platey surface and fracture coatings, in vugs or cavities, rarely as crusts of crystals – prismatic to tabular, may be wedge-shaped
Cleavage
Perfect on {010}
Mohs scale hardness
5.5
Luster
Brilliant, glassy; pearly on {010}
Streak
white
Diaphaneity
Transparent to translucent
Specific gravity
3.28–3.33
Optical properties
Biaxial (−)
Refractive index
nα = 1.662 nβ = 1.667 nγ = 1.669
Ultraviolet fluorescence
UV=orange
Other characteristics
Strongly pyroelectric
References
[2][3][4][5]
Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic system and typically occurs as veinlets and fracture coatings. It is commonly colorless, white to pale amethyst in color. It has perfect cleavage and the crystalline habit has a brilliant luster. It has a Mohs hardness of 5.5 and a specific gravity of 3.28–3.33.[3][4]
Under short wave ultraviolet light it fluoresces a rich orange color. It is frequently associated with minerals such as hardystonite (fluoresces violet blue), esperite (fluoresces bright yellow), calcite (fluoresces orange-red), franklinite (non-fluorescent) and willemite (fluoresces green).[6]
Clinohedrite was found primarily at the Franklin zinc mines in New Jersey, the type locality, but has also been reported from the Christmas mine, Gila County, Arizona,[3] and the Western Quinling gold belt, Gansu Province, China.[4]
It was first described in 1898 and was named for its crystal morphology from the Greek klino for incline, and hedra for face.[3]
Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic...
green), calcite (fluoresces red), and clinohedrite (fluoresces orange). Hardystonite can be found altered to clinohedrite CaZn(SiO4)·H2O through direct hydrothermal...
shaft just under Franklin Falls. Other rare minerals include esperite, clinohedrite, hardystonite, and others. There are scores of minerals found only here...
in association with calcite, franklinite, willemite, hardystonite and clinohedrite. It has also been found as prismatic crystals up to 1 mm in length at...
fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite. Hexavalent uranium, in the form of the uranyl cation (UO2+ 2), fluoresces...
Associated minerals include apophyllite, diopside, stilbite, tobermorite, clinohedrite, thaumasite, laumontite and wollastonite. The most common impurities...
were up to 6mm in length and were suspected to have grown alongside clinohedrite crystals. The other location where charlesite has been located is the...
wollastonite, garnet, diopside, willemite, johannsenite, margarosanite and clinohedrite also may be present. Bustamite typically results from metamorphism of...
the mineral, was given to C. H. Warren in 1897. First thought to be clinohedrite deeply colored by manganese, it was identified as a new mineral in 1899...
others) were the new minerals Nesquehonite, Canfieldite, Pearceite, Clinohedrite, Hancockite, Glaucochroite, Graftonite, as well as known minerals that...
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