Scorodite Value, Price, and Jewelry Information


Scorodite: Tsumeb, Namibia (1.15, 1.50). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Gems of scorodite are extremely rare (usually Tsumeb), but cut stones have a lovely color and intense pleochroism. Too soft to wear, the stone is suited for collectors of the rare and unusual.

Scorodite Value

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Scorodite Information

DataValue
NameScorodite
Is a Variety ofVariscite
Crystallography Orthorhombic. Crystals pyramidal, tabular, prismatic; massive, crusts.
Colors Pale grayish green, yellowish brown to brown, colorless, bluish green, blue, violet.
Luster Vitreous to resinous.
Fracture Subconchoidal. Brittle.
Hardness 3.5-4.
Specific Gravity 3.28-3.29.
Cleavage Imperfect.
Stone SizesCut gems are always small, mostly from Tsumeb material. The maximum to expect is about 5 carats but even this would be very large for the species. Smithsonian Institution (Washington, D.C): 2.6 (purplish, Namibia).
Luminescence None. Soluble in HCl.
Spectral One line at 4500, broad absorption in the green (Tsumeb).
FormulaFeAsO4 – 2H2O.
Pleochroism Intense: purplish/bluish (Tsumeb).

SCORODITE Series to Mansfieldite: AlAsO4 · 2H2O.

Properties of Scorodite from Various Localities

α

β

γ

Birefringence

2V

Durango, Mexico

1.784

1.795

1.814

0.030

75°

Idaho

1.738

1.742

1.765

0.027

60°

Oregon

1.741

1.744

1.768

0.027

40°

Tsumeb, Namibia

1.785

1.796

1.816

0.031

75°Optics: Biaxial (+), variable 2V.

Occurrence: A secondary mineral resulting from the oxidation of arsenious ores.

Utah; South Dakota; California; Washington; Idaho;

Nevada; Wyoming.

Ontario, Canada; Japan; England.

Durango, Mexico; fine blue crystals.

Ouro Preto, Minas Gerais, Brazil:  good crystals, some gemmy.

Tsumeb, Namibia: pleochroic blue crystals, to 25 mm long, some gemmy.

Comments: Gems of scorodite are extremely rare (usually Tsumeb), but cut stones have a lovely color and intense pleochroism. Too soft to wear, the stone is suited for collectors of the rare and unusual.

Name: From the Greek for garliclike because the material emits the typical garlic odor of arsenic when heated.