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 veins and as secondary mine ...

. It was discovered in the

Tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...

deposit of Nura-Taldy in

Karaganda Region Karaganda Region ( kk, Qarağandy oblysy; russian: Карагандинская область, translit=Karagandinskaja oblast′), also spelled Qaraghandy Region, is a region of Kazakhstan. Its capital is Karaganda. On 17 March 2022 it was an ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

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 Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is Cu4SO4(OH)6. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it was named by Armand Lévy for his fellow Frenchman, geologist ...

, langite,

devilline Devilline is a sulfate mineral with the chemical formula CaCu4(SO4)2(OH)6•3H2O. The name originates from the French chemist's name, Henri Etienne Sainte-Claire Deville (1818–1881). Devilline crystallizes in the monoclinic system. Crystallogr ...

serpierite Serpierite () is a rare, sky-blue coloured hydrated sulfate mineral, often found as a post-mining product. It is a member of the devilline group, which has members aldridgeite , campigliaite , devilline , kobyashevite , lautenthalite and an ...

, 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. Occurrence Aurichalcite typically occurs in the oxidized zone of copper and z ...

azurite Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the Type locality (geology), type locality at Chessy, Rhône, Chessy-les-Mines near ...

malachite Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures ...

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 hardness of 3.5 to 4 on the Mo ...

References

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