Category
page 1Minerals in space group 31
bournonite
Bournonite, also axotomous antimony glance, wheel ore, berthonite, volchite or dystomic glance () is a sulfosalt mineral species, trithioantimoniate of lead and copper with the formula PbCuSbS3.
enargite
Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word 'distinct'. Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45.
caledonite
Caledonite, whose name derives from Caledonia, the historical name of its place of discovery (Scotland), is a richly colored blue-green sulfate-carbonate mineral of lead and copper with an orthorhombic crystal structure. It is an uncommon mineral found in the oxidized zones of copper-lead deposits.

struvite
Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
guilleminite
Guilleminite (Ba(UO2)3(SeO3)2(OH)4·3H2O) is a uranium mineral named by R. Pierrot, J. Toussaint, and T. Verbeek in 1965 in honor of Jean Claude Guillemin (1923–1994), a chemist and mineralogist. It is a rare uranium/selenium mineral found at the Musonoi Mine in the Katanga Province of the Democratic Republic of the Congo.
derriksite
Derriksite is a very rare uranium mineral with the chemical formula Cu4(UO2)(SeO3)2(OH)6•H2O. It is a secondary mineral that contains copper, uranium and the rarer selenium. It is a bright green to duller bottle green colour. Its crystal habit is acicular, it is most likely to be found along with the uranyl selenium mineral demesmaekerite, but derriksite is much rarer than demesmaekerite. It is named after Jean Marie Francois Joseph Derriks (1912–1992), geologist and administrator of the Union Minière du Haut Katanga (UMHK). It has a Mohs hardness of about 2.
parnauite
Parnauite is a very rare secondary copper arsenate–sulfate mineral. It forms near the Earth's surface in oxidized zones of various copper deposits. These copper minerals are altered by oxygen-rich water and new minerals grow as a thin coatings or small crystal clusters. Parnauite is typically blue-green to green and commonly occurs as tiny bladed crystals in fan-shaped sprays or rosettes. It may also appear as scaly crusts or crystal-like surface films.
nevadaite
Nevadaite is a rare phosphate mineral with a chemical formula of
{|
|Cu2Zn0.02V3+0.98Al1.15Al8P7.9O32F8.37(OH)1.63(H2O)21.65
|-
|}
fermiite
Fermiite is a rare uranium mineral with the formula Na4(UO2)(SO4)3·3H2O. Chemically related minerals include oppenheimerite, meisserite (which is also structurally-related to fermiite), belakovskiite, natrozippeite and plášilite. Fermiite comes from the Blue Lizard mine, San Juan County, Utah, USA, which is known for many rare uranium minerals. The name honors Enrico Fermi (1901–1954).