Scorodite Value, Price, and Jewelry Information
With lovely colors and intense pleochroism, faceted scorodite is a prize for collectors of the rare and unusual. However, it’s too soft for jewelry use.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Is a Variety of||Variscite|
|Crystallography||Orthorhombic. Crystals pyramidal, tabular, prismatic; massive, crusts.|
|Refractive Index||Varies by locality, 1.738-1.816. See "Identifying Characteristics" below.|
|Colors||Pale grayish green, yellowish brown to brown, colorless, blueish green, blue, violet.|
|Luster||Vitreous to resinous.|
|Birefringence||Varies by locality, 0.027-0.031. See "Identifying Characteristics" below.|
|Transparency||Translucent to Semi-Transparent.|
|Absorption Spectrum||One line at 4500, broad absorption in the green (Tsumeb).|
|Phenomena||Color change (very rare).|
|Formula||Fe3+AsO4 · 2H2O|
|Pleochroism||Intense: purplish/bluish (Tsumeb).|
|Optics||Biaxial (+), variable 2V. See "Identifying Characteristics" below.|
|Etymology||From the Greek skorodon for “garlic,” because the material emits the typical garlic odor of arsenic when heated.|
|Occurrence||A secondary mineral resulting from the oxidation of arsenious ores.|
Although not a rare mineral, faceted scorodites are extremely rare. A low Mohs hardness score of 3.5 to 4 and imperfect cleavage make them very susceptible to scratches and blows. Thus, faceted pieces would make interesting collector’s gems rather than practical jewelry stones.
Rare specimens display color change, from blue-green in daylight to blueish purple or grayish blue in incandescent light.
Optical Properties of Scorodite from Various Localities
Consumers may encounter so-called “scorolites” for sale online. Often marketed as “scorolite opals,” they are, in fact, simulants, usually purplish glass or quartz pieces. Occasionally, you might encounter this same material offered as scorodite. Keep in mind that “scorolite” is not a synonym or alternate name for scorodite. Quartz and glass are distinct gemologically from scorodites. (This confusion may stem from a typo in a paper on geo-environmental hazards in groundwater in India).
Tsumeb, Namibia produces beautiful, pleochroic blue/purplish crystals, some gemmy, up to 25 mm long.
Durango, Mexico and Ouro Preto, Minas Gerais, Brazil also yield fine, blue crystals, some gemmy.
Other notable crystal sources include
- United States: California; Idaho; Nevada; Oregon; South Dakota; Utah; Washington; Wyoming.
- Algeria; Ontario, Canada; China; Japan; Portugal; United Kingdom.
Scorodites almost always make small faceted gems. As a reasonable maximum, expect about five carats. However, even that would be very large for the species.
- Smithsonian Institution (Washington, DC): 2.6 (purplish, Namibia).
Scorodites just don’t have the wearability to serve as jewelry stones. Furthermore, they’re soluble in acids and contain arsenic. While this shouldn’t pose a problem for wear or display, gem cutters should take precautions to prevent inhaling particles, protect their eyes, and wash their hands while working with scorodites.