Adamite Value, Price, and Jewelry Information


adamite - ojuela
Adamite: Ojuela Mine, Mapimi, Mexico (0.86). Photo © Joel E. Arem, PhD, FGA. Used with permission.

 Exceedingly rare as a cut gem, although the mineral occurs in many localities. Much too soft and fragile for jewelry; strictly a collector item.

Adamite Value

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Adamite Information

DataValue
NameAdamite
Crystallography Orthorhombic; crystals elongated or equant; druses, radial aggregates, and spheroids on matrix.
Colors Colorless, pale green, yellowish green, yellow (various shades), bluish green, green (contains Cu); rose and violet shades (color zoned, contains Co).
Luster Vitreous
Fracture Subconchoidal to uneven.
Hardness 3.5
Specific Gravity 4.32-4.68 (red-violet)
Cleavage Good 1 direction.
Dispersion Strong
Stone SizesViolet crystals noted up to 1 cm long and transparent, would yield stones up to about 1-2 carats. Green material usually not clean, would provide only small faceted gems (1-3 carats). PC: 4.38 (pink, Mexico)
Luminescence Intense green in SW, LW; also lemon yellow in SW.
Spectral Not diagnostic.
FormulaZn2(AsO4)OH + Co, Cu.
Pleochroism Colorless/ blue-green/yellow-green. Pale rose/ pale rose/ pale purple. Pink/ pale rose/colorless.

Comments: Exceedingly rare as a cut gem, although the mineral occurs in many localities. Much too soft and fragile for jewelry; strictly a collector item.

Locality

α

β

γ

Birefringence

Mapimi, Mexico (reddish)

1.712

1.736

1.760

0.048

Mapimi, Mexico (rose)

1.710

1.735

1.759

0.049

Mapimi, Mexico (violet)

1.710

1.735

1.758

0.048

Mapimi, Mexico (green)

1.722

1.742

1.763

0.041

Tsumeb, Namibia (Cu)

1.742

1.768

1.773

0.031

Tsumeb, Namibia (Co)

1.722

1.738

1.761

0.039

Laurium, Greece

1.708

1.734

1.758

0.050

Biaxial  (+); 2V = 15° (Cu. Var.) to 88°

Large variations in composition lead to wide variations in optical properties.

Occurrence: Secondary mineral in the oxidized zone of ore deposits.

Utah (various localities); California; Nevada.

Laurium, Greece: often containing copper, in lovely blue and green shades.

Mapimi, Mexico: fine sprays of crystals in limonite matrix, from the Ojuela Mine.

Tsumeb, Namibia: fine crystals, sometimes colored purple by cobalt.

Cap Garonne, France.

Also Chile, Italy, Germany, Turkey, Algeria.

Comments: Exceedingly rare as a cut gem, although the mineral occurs in many localities. Much too soft and fragile for jewelry; strictly a collector item.

Name: After Mr. Gilbert Adam, mineralogist, of Paris, who supplied the first specimens for study.