Adamite

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Adamite
Adamite-179841.jpg
Yellow-green adamite in limonite
General
Category Arsenate mineral
Formula
(repeating unit)
Zn2AsO4OH
IMA symbol Ad [1]
Strunz classification 8.BB.30
Dana classification41.06.06.03
Olivenite group
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H–M symbol: (2/m 2/m 2/m)
Space group Pnnm
Identification
ColorPale yellow, honey-yellow, brownish yellow, reddish; rarely white, colorless, blue, pale green to green, may be zoned
Crystal habit Wedge-like prisms typically in druses and radiating clusters; also smooth botryoidal masses
Cleavage {101}, good; {010}, poor
Fracture Uneven to subconchoidal
Tenacity Brittle
Mohs scale hardness3.5
Luster Vitreous
Streak White to pale green
Specific gravity 4.32–4.48 measured
Optical propertiesBiaxial (+/−)
Refractive index nα=1.708 – 1.722, nβ=1.742 – 1.744, nγ=1.763 – 1.773
Birefringence δ = 0.055
Other characteristicsMay fluoresce and phosphoresce lemon-yellow under SW and LW UV.
References [2] [3] [4]

Adamite is a zinc arsenate hydroxide mineral, Zn 2 As O 4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.

Contents

Adamite on limonite from the Gold Hill District Tooele County, Utah, US. Scale at bottom is c. 2.5 cm. Adamite - Gild Hill, Deep Creek Mountains, Tooele County, Utah, USA.jpg
Adamite on limonite from the Gold Hill District Tooele County, Utah, US. Scale at bottom is c. 2.5 cm.

Occurrence

Adamite occurs as a secondary mineral in the oxidized zone of zinc- and arsenic-bearing hydrothermal mineral deposits. It occurs in association with smithsonite, hemimorphite, scorodite, olivenite, calcite, quartz and iron and manganese oxides. [2]

The yellow to bright lime-green colored crystals and druze along with its distinctive fluorescence make adamite a favorite among mineral collectors. Found in Mapimí, Durango, Mexico; Greece; and California and Utah in the United States.

Adamite was named after the French mineralogist Gilbert-Joseph Adam (1795–1881). It was first described in 1866 for an occurrence at the type locality of Chañarcillo, Copiapó Province, Atacama Region, Chile. [3]

See also

Related Research Articles

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Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn,Cu)5(CO3)2(OH)6. The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors.

<span class="mw-page-title-main">Erythrite</span> Hydrated cobalt arsenate mineral

Erythrite or red cobalt is a secondary hydrated cobalt arsenate mineral with the formula Co
3
(AsO
4
)
2
•8H
2
O
. Erythrite and annabergite, chemical formula Ni
3
(AsO
4
)
2
•8H
2
O
, or nickel arsenate form a complete series with the general formula (Co,Ni)
3
(AsO
4
)
2
•8H
2
O
.

<span class="mw-page-title-main">Tephroite</span>

Tephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn2SiO4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.

<span class="mw-page-title-main">Olivenite</span> Copper arsenate mineral

Olivenite is a copper arsenate mineral, formula Cu2AsO4OH. It crystallizes in the monoclinic system (pseudo-orthorhombic), and is sometimes found in small brilliant crystals of simple prismatic habit terminated by domal faces. More commonly, it occurs as globular aggregates of acicular crystals, these fibrous forms often having a velvety luster; sometimes it is lamellar in structure, or soft and earthy.

<span class="mw-page-title-main">Liroconite</span> Copper aluminium arsenate mineral

Liroconite is a complex mineral: Hydrated copper aluminium arsenate hydroxide, with the formula Cu2Al[(OH)4|AsO4]·4(H2O). It is a vitreous monoclinic mineral, colored bright blue to green, often associated with malachite, azurite, olivenite, and clinoclase. It is quite soft, with a Mohs hardness of 2–2.5, and has a specific gravity of 2.9–3.0.

<span class="mw-page-title-main">Descloizite</span> Mineral

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. Appreciable gallium and germanium may also be incorporated into the crystal structure.

<span class="mw-page-title-main">Legrandite</span>

Legrandite is a rare zinc arsenate mineral, Zn2(AsO4)(OH)·(H2O).

Reinerite is a rare arsenite (arsenate(III)) mineral with chemical formula Zn3(AsO3)2. It crystallizes in the orthorhombic crystal system.

<span class="mw-page-title-main">Conichalcite</span> Arsenate mineral

Conichalcite, CaCu(AsO4)(OH), is a relatively common arsenate mineral related to duftite (PbCu(AsO4)(OH)). It is green, often botryoidal, and occurs in the oxidation zone of some metal deposits. It occurs with limonite, malachite, beudantite, adamite, cuproadamite, olivenite and smithsonite.

<span class="mw-page-title-main">Zeunerite</span>

Zeunerite is a green copper uranium arsenate mineral with formula Cu(UO2)2(AsO4)2·(10-16)H2O. It is a member of the autunite group. The associated mineral metazeunerite is a dehydration product of zeunerite.

<span class="mw-page-title-main">Ashburtonite</span>

Ashburtonite is a rare lead copper silicate-bicarbonate mineral with formula: HPb4Cu2+4Si4O12(HCO3)4(OH)4Cl.

<span class="mw-page-title-main">Beudantite</span> Secondary mineral of the alunite group

Beudandite is a secondary mineral occurring in the oxidized zones of polymetallic deposits. It is a lead, iron, arsenate, sulfate with endmember formula: PbFe3(OH)6SO4AsO4.

<span class="mw-page-title-main">Eveite</span> Manganese arsenate mineral

Eveite is a manganese arsenate mineral in the olivenite group. Its chemical formula is Mn2AsO4OH. It is found only in Långban, Filipstad, Värmland, Sweden and at the Sterling Mine in New Jersey, United States. It is a dimorph of sarkinite and is isostructural with adamite. The name, for the biblical "Eve", comes from its structural similarities to adamite and is also a reference to its apple-green color. It can also be pale yellow. Eveite is an orthorhombic mineral, which means it has three crystallographic axes of unequal lengths which are at 90° to one another.

<span class="mw-page-title-main">Warikahnite</span> Rare zinc arsenate mineral

Warikahnite is a rare zinc arsenate mineral of the triclinic crystal system with Hermann-Mauguin notation 1, belonging to the space group P1. It occurs in the Tsumeb mine in Namibia on corroded tennantite in the second oxidation zone under hydrothermal conditions in a dolomite-hosted polymetallic ore deposit. It is associated with adamite, stranskiite, koritnigite, claudetite, tsumcorite, and ludlockite. The origin of discovery was in a dolomite ore formation within an oxidized hydrothermal zone, in the E9 pillar, 31st level of the Tsumeb Mine in Namibia, Southwest Africa. It has also been found at Lavrion, Greece and Plaka, Greece as microscopic white needles.

<span class="mw-page-title-main">Tsumcorite</span>

Tsumcorite is a rare hydrated lead arsenate mineral that was discovered in 1971, and reported by Geier, Kautz and Muller. It was named after the TSUMeb CORporation mine at Tsumeb, in Namibia, in recognition of the Corporation's support for mineralogical investigations of the orebody at its Mineral Research Laboratory.

<span class="mw-page-title-main">Cornwallite</span> Copper arsenate mineral

Cornwallite is an uncommon copper arsenate mineral with formula Cu5(AsO4)2(OH)4. It forms a series with the phosphate pseudomalachite and is a dimorph of the triclinic cornubite. It is a green monoclinic mineral which forms as radial to fibrous encrustations.

<span class="mw-page-title-main">Zincolivenite</span>

Zincolivenite is a copper zinc arsenate mineral with formula CuZn(AsO4)(OH) that is a member of the olivenite group. Its colors range from green to blue, and its name comes from its composition of zinc and olivenite.

<span class="mw-page-title-main">Köttigite</span>

Köttigite is a rare hydrated zinc arsenate which was discovered in 1849 and named by James Dwight Dana in 1850 in honour of Otto Friedrich Köttig (1824–1892), a German chemist from Schneeberg, Saxony, who made the first chemical analysis of the mineral. It has the formula Zn3(AsO4)2·8H2O and it is a dimorph of metaköttigite, which means that the two minerals have the same formula, but a different structure: köttigite is monoclinic and metaköttigite is triclinic. There are several minerals with similar formulae but with other cations in place of the zinc. Iron forms parasymplesite Fe2+3(AsO4)2·8H2O; cobalt forms the distinctively coloured pinkish purple mineral erythrite Co3(AsO4)2·8H2O and nickel forms annabergite Ni3(AsO4)2·8H2O. Köttigite forms series with all three of these minerals and they are all members of the vivianite group.

<span class="mw-page-title-main">Arsendescloizite</span> Lead-zinc mineral

Arsendescloizite is a lead-zinc mineral, approved by the IMA in 1982. It is an arsenate analog of descloizite. Its first description was published in 1982.

<span class="mw-page-title-main">Mawbyite</span>

Mawbyite is a lead iron zinc arsenate that was named in honor of Maurice Alan Edgar Mawby. It has been approved by the IMA in 1988, and was published just a year after being described by Pring. Mawbyite is a member of the tsumcorite group, the monoclinic dimorph of carminite. It was first believed to be tsumcorite; however, crystal-structure determination showed iron and zinc occupying the same crystallographic site instead, and through the analysis it turned out mawbyite is isostructural with tsumcorite, meaning the two share a similar formula. More accurately, mawbyite appears to be the ferric analogue of the aforementioned mineral. The relationship between helmutwinklerite – which shares a similar formula with tsumcorite's – and mawbyite had been suggested, but due to lack of data it remains unclear. A full crystal-structure analysis is required in order to understand the relationship between their structures.

References

  1. Warr, L. N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
  2. 1 2 http://rruff.geo.arizona.edu/doclib/hom/adamite.pdf Handbook of Mineralogy
  3. 1 2 http://www.mindat.org/min-21.html Mindat.org
  4. http://webmineral.com/data/Adamite.shtml Webmineral data