Posnjakite is a hydrated copper

sulfate mineral The sulfate minerals are a class of minerals that include the sulfate ion () within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal Vein (geology), veins and as ...

. It was discovered in the

Tungsten Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

deposit of Nura-Taldy in

Karaganda Region Karaganda Region (; ) is a region of Kazakhstan. Its capital is Karaganda. The region borders Akmola and Pavlodar Region to the north, Abai Region to the east, Jetisu, Almaty, and Zhambyl Regions to the south, and Kostanay and Ulytau regio ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

and described in 1967 by Aleksandr Ivanovich Komkov (1926–1987) and Yevgenii Ivanovich Nefedov (1910–1976) and named after geochemist Eugene Valdemar Posnjak (1888–1949).MINER Database, (c) Jacques Lapaire - Minéraux et étymologie

Occurrence

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 Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is . The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors. Occurrence Aurichalci ...

azurite Azurite or '' Azure spar'Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0. ''(in Russian)'' is a soft, deep-blue copp ...

malachite Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often for ...

and

chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a Mohs scale, hardness of 3.5 to 4 ...

References

{{Reflist Copper(II) minerals Sulfate minerals Monoclinic minerals Minerals in space group 7 Minerals described in 1967