Hydrated cobalt arsenate known as cobalt bloom for its vivid crimson-purple color. Important prospecting indicator for cobalt. Color: Crimson red, pink, purple. Luster: Vitreous to pearly. Streak: Pale pink. Cleavage: Perfect in one direction. Hardness: 1.5-2.5. Transparency: Transparent to translucent. Crystal system: Monoclinic. Chemical formula: Co₃ AsO₄ ₂·8H₂O. Specific gravity: 3.06. Formation: Forms as a weathering product of cobalt arsenide minerals skutterudite, cobaltite in the oxidation zone. Common geological settings: Morocco, Germany, Canada, Mexico; found in oxidized cobalt-nickel-arsenic deposits. Common look-alikes and related entries: Vivianite, Cobaltoan Calcite, Purpurite. Specimen safety: Keep this arsenic-bearing specimen intact. Do not cut, grind, polish, streak, lick, heat, or use acid on it. Avoid creating or breathing dust or fumes, wash your hands with soap and water after handling, and keep it away from food, children, and pets.
Previous: Epidote — Calcium aluminum iron silicate with a characteristic pistachio-green color. Common metamorphic and hydrothermal mineral.
Next: Feldspar — The most abundant mineral group in the Earth's crust, making up about 60% of all rocks. Feldspars are essential constituents of igneous, metamorphic, and…
These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
Editorial owner
GeoMiner
Last updated
2026-03-30T14:37:35.808251+00:00
Review status
Published; not independently peer-reviewed
IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
Arsenic (inorganic compounds, as As) — CDC/NIOSH. Official occupational-hazard, exposure-route, symptom, and protective-equipment information for inorganic arsenic compounds.
Hydrated cobalt arsenate known as cobalt bloom for its vivid crimson-purple color. Important prospecting indicator for cobalt.
How can you identify Erythrite?
Compare several properties rather than relying on colour alone. This entry records colour: Crimson red, pink, purple; lustre: Vitreous to pearly; streak: Pale pink; Mohs hardness: 1.5-2.5; cleavage: Perfect in one direction; crystal system: Monoclinic; transparency: Transparent to translucent. Confirm an important identification with additional field tests or qualified laboratory work.
How does Erythrite form?
Forms as a weathering product of cobalt arsenide minerals skutterudite, cobaltite in the oxidation zone.
Where is Erythrite commonly found?
Morocco, Germany, Canada, Mexico; found in oxidized cobalt-nickel-arsenic deposits.
Is Erythrite safe to handle?
Keep this arsenic-bearing specimen intact. Do not cut, grind, polish, streak, lick, heat, or use acid on it. Avoid creating or breathing dust or fumes, wash your hands with soap and water after handling, and keep it away from food, children, and pets. Avoid creating dust or using destructive tests on an unknown specimen, and follow site-specific safety procedures.
What is Erythrite commonly confused with?
Erythrite may be confused with Vivianite, Cobaltoan Calcite, Purpurite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
JavaScript is loading the interactive GeoMiner experience. The identification tools provide educational candidates, not laboratory confirmation.
