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 ...
in
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