Paratacamite

Paratacamite
Paratacamite from Cornwall, England
General
Category	Halide mineral
Formula	Cu3(Cu,Zn)(OH)6Cl2
IMA symbol	Pata [1]
Strunz classification	III / D.01-55
Crystal system	Trigonal
Crystal class	Rhombohedral
Unit cell	a = 13,654, c = 14,041;
Identification
Formula mass	58.433 g/mol
Color	Green
Cleavage	Very good
Fracture	Conchoidal
Mohs scale hardness	3
Luster	Vitreous
Streak	Green
Diaphaneity	Transparent
Specific gravity	3.74
Density	3.74g/cm3
Solubility	Acid-soluble
References	[2]

Paratacamite is a mineral in the halide minerals category. Its chemical formula is Cu₃(Cu,Zn)(OH)₆Cl₂. Its name is derived from its association with atacamite. Paratacamite was first described by Herbert Smith in 1906. ^[3] The zincian endmember Cu₃(Zn)(OH)₆Cl₂ is called herbertsmithite, and paratacamite is polymorphous with botallackite and atacamite. ^[4]

It has been found in Chile, Botallack Mine in Cornwall, Broken Hill, Australia, and in Italy at Capo Calamita on the island of Elba. ^[2]

See also

• Atacamite

References

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
2. "Paratacamite: Paratacamite mineral information and data". mindat.org. Retrieved 2017-09-20.
3. Smith, G.F.H.; Prior, G.T. (1906). "Paratacamite, a new oxychloride of copper". Mineralogical Magazine. 14 (65): 170–177. Bibcode:1906MinM...14..170S. doi:10.1180/minmag.1906.014.65.09.
4. Braithwaite, RSW; Mereiter, K; Paar, WH; Clark, AM (1004). "Herbertsmithite, Cu3Zn(OH)6Cl2, a new species, and the definition of paratacamite" (PDF). Mineralogical Magazine. 68 (3): 527–539. doi:10.1180/0026461046830204.