Posnjakite | |
---|---|
General | |
Category | Copper minerals |
Formula (repeating unit) | Cu4[(OH)6|SO4] • H2O |
IMA symbol | Pnk [1] |
Strunz classification | 7.DD.10 |
Dana classification | 31.4.1.1 |
Crystal system | Monoclinic |
Crystal class | Domatic (m) (same H-M symbol) |
Space group | Pa |
Unit cell | a = 10.578 Å, b = 6.345 Å, c = 7.863 Å; β = 117.98°; Z = 2 [2] |
Identification | |
Formula mass | 488.32 g/mol |
Color | Sky-blue to dark-blue |
Crystal habit | Crystals scaly, or as crusts; earthy |
Mohs scale hardness | 2 to 3 |
Luster | Vitreous |
Refractive index | nα = 1.625 nβ = 1.680 nγ = 1.706 [2] |
References | [3] |
Posnjakite is a hydrated copper sulfate mineral. It was discovered in the Tungsten deposit of Nura-Taldy [4] in Karaganda Region in Kazakhstan and described in 1967 by Aleksandr Ivanovich Komkov (1926–1987) and Yevgenii Ivanovich Nefedov (1910–1976) [5] and named after geochemist Eugene Valdemar Posnjak (1888–1949). [6]
Posnjakite is an uncommon but widespread secondary mineral in the oxidised zone of copper sulfide deposits, which may be of post-mine formation. It is associated with brochantite, langite, devilline, serpierite, woodwardite, wroewolfeite, aurichalcite, azurite, malachite and chalcopyrite. [4]
Posnjakite | |
---|---|
General | |
Category | Copper minerals |
Formula (repeating unit) | Cu4[(OH)6|SO4] • H2O |
IMA symbol | Pnk [1] |
Strunz classification | 7.DD.10 |
Dana classification | 31.4.1.1 |
Crystal system | Monoclinic |
Crystal class | Domatic (m) (same H-M symbol) |
Space group | Pa |
Unit cell | a = 10.578 Å, b = 6.345 Å, c = 7.863 Å; β = 117.98°; Z = 2 [2] |
Identification | |
Formula mass | 488.32 g/mol |
Color | Sky-blue to dark-blue |
Crystal habit | Crystals scaly, or as crusts; earthy |
Mohs scale hardness | 2 to 3 |
Luster | Vitreous |
Refractive index | nα = 1.625 nβ = 1.680 nγ = 1.706 [2] |
References | [3] |
Posnjakite is a hydrated copper sulfate mineral. It was discovered in the Tungsten deposit of Nura-Taldy [4] in Karaganda Region in Kazakhstan and described in 1967 by Aleksandr Ivanovich Komkov (1926–1987) and Yevgenii Ivanovich Nefedov (1910–1976) [5] and named after geochemist Eugene Valdemar Posnjak (1888–1949). [6]
Posnjakite is an uncommon but widespread secondary mineral in the oxidised zone of copper sulfide deposits, which may be of post-mine formation. It is associated with brochantite, langite, devilline, serpierite, woodwardite, wroewolfeite, aurichalcite, azurite, malachite and chalcopyrite. [4]