Descloizite specimen from Berg Aukas (Berg Aukus), Namibia, 9.5 x 8.9 x 4.9 cm
General
Category
Vanadate mineral
Formula (repeating unit)
(Pb,Zn)2VO4OH
IMA symbol
Dcz[1]
Strunz classification
8.BH.40
Crystal system
Orthorhombic
Crystal class
Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group
Pnma (no. 62)
Unit cell
a = 7.593, b = 6.057 c = 9.416 [Å]; Z = 4
Identification
Color
Brownish red, red-orange, reddish to blackish brown, nearly black
Crystal habit
Zoned tabular crystals common, encrustations and plumose aggregates
Cleavage
None
Fracture
Irregular, sub-conchoidal
Tenacity
Brittle
Mohs scale hardness
3 – 3.5
Luster
Greasy
Streak
Orange to brownish red
Diaphaneity
Transparent to opaque
Specific gravity
6.1 – 6.2
Optical properties
Biaxial (−)
Refractive index
nα = 2.185 nβ = 2.265 nγ = 2.350
Birefringence
δ = 0.165
Pleochroism
Visible
2V angle
85° to 90°
Dispersion
Strong r > v rarely r < v
References
[2][3][4]
Descloizite is a rare mineral species consisting of basic lead and zinc vanadate, (Pb, Zn)2(OH)VO4, crystallizing in the orthorhombic crystal system and isomorphous with olivenite.[5] Appreciable gallium and germanium may also be incorporated into the crystal structure.
The color is deep cherry-red to brown or black, and the crystals are transparent or translucent with a greasy lustre; the streak is orange-yellow to brown; specific gravity 5.9 to 6.2; hardness 31/2. A variety known as cuprodescloizite is dull green in color; it contains a considerable amount of copper replacing zinc and some arsenic replacing vanadium.[5] There is also an arsenate analogue called arsendescloizite.[6]
^"Handbook of Mineralogy" (PDF). Archived from the original (PDF) on 2021-02-27. Retrieved 2010-11-15.
^ abOne or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Descloizite". Encyclopædia Britannica. Vol. 8 (11th ed.). Cambridge University Press. p. 91.
Descloizite is a rare mineral species consisting of basic lead and zinc vanadate, (Pb, Zn)2(OH)VO4, crystallizing in the orthorhombic crystal system and...
arsenate analog of descloizite. Its first description was published in 1982. Arsendescloizite belongs to the adelite-descloizite group. It is the arsenate...
vanadate hydroxide mineral, PbCu(VO4)(OH), at the copper end of the descloizite subgroup. It was formerly called cuprodescloizite or psittacinite (this...
Christian VIII of Denmark). In 1854, Alexis Damour dedicated the mineral descloizite in honor of Des Cloizeaux. Des Cloizeaux was elected as a member of the...
Austinite is a member of the adelite-descloizite group, adelite subgroup, the zinc (Zn) end member of the copper-Zn series with conichalcite. It is the...
minerals Blodite group Calcite group Cancrinite group Clay minerals group Descloizite group Dolomite group Epidote group Feldspar group Feldspathoid Garnet...
found in ore deposits in Algeria, Germany, Italy, Sweden and the US. Descloizite List of minerals Look up adelite in Wiktionary, the free dictionary....
"lined with beautiful crystals of pyromorphite and cerussite", as well as descloizite and vanadinite. The Kabwe deposit is a carbonate hosted lead-zinc deposit...
anglesite, smithsonite, hemimorphite, vanadinite, pyromorphite, mimetite, descloizite, plattnerite and various iron and manganese oxides. A noted locality...
Vuagnatite is a member of the adelite-descloizite group which was named after Prof. Dr. Marc Bernard Vuagnat. Its type locality is in Turkey, at Bögürtlencik...
and often forms botryoidal aggregates. It is a member of the adelite-descloizite Group, Conichalcite-Duftite Series. Duftite and conichalcite specimens...
jacobsite and alluaudite, to name a few. In 1854 he named the mineral descloizite in honor of Alfred Des Cloizeaux. In 1845 Achille Ernest Oscar Joseph...
Pb2Cu5(UO2)2(SeO3)6(OH)6·2H2O – Belgian geologist Gaston Demesmaeker (1911–1997) Descloizite: PbZnVO4(OH) – Alfred Lewis Oliver Legrand Des Cloizeaux (1817–1897)...
oxidized zinc deposits. It has been found in association with cerussite, descloizite, hemimorphite, hopeite, hydrozincite, "limonite", parahopeite, pyromorphite...
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