Quick Facts
Formation & Origin
Angelite is a trade name for blue anhydrite - the anhydrous (waterless) form of calcium sulfate. Gypsum is the hydrated form (CaSO₄·2H₂O); when gypsum loses its water through burial, heat, or pressure, it converts to anhydrite (CaSO₄). The blue color in angelite comes from trace amounts of strontium or iron impurities.
Anhydrite forms in evaporite deposits alongside gypsum, halite (rock salt), and other evaporite minerals. These deposits represent ancient seas or salt lakes that evaporated, concentrating dissolved minerals. The conversion from gypsum to anhydrite occurs at depths of around 600 meters where temperatures and pressures are sufficient to drive off the crystal water.
Angelite has an important practical quirk: it converts back to gypsum when exposed to water for extended periods. This means angelite should never be cleansed in water, worn in the shower, or left in humid environments - it will gradually soften, whiten, and deteriorate.
Identification Guide
Angelite is identified by its distinctive soft periwinkle-blue color, waxy luster, and low hardness (3.5). It often has a slightly chalky feel and appearance compared to harder blue minerals.
Distinguish from celestite (crystalline rather than massive, higher SG at 3.97), blue calcite (fizzes in acid), and blue lace agate (much harder at 7, banded pattern). Angelite's combination of blue color, low hardness, massive habit, and water sensitivity is diagnostic.
Spotting Fakes
Angelite is inexpensive and rarely faked. The main issue is distinguishing it from blue-dyed stones - genuine angelite has a natural, slightly uneven color distribution. It's sometimes confused with or sold interchangeably as celestite, but they're chemically different (celestite is strontium sulfate). The water sensitivity is both a practical concern and an identification test - genuine angelite will show surface changes if left in water.
Cultural & Metaphysical Traditions
Presented as cultural traditions, not scientific evidence
The 'angelite' trade name was coined to market blue anhydrite for the crystal healing market, connecting the stone's ethereal blue color to angelic communication. It has no ancient historical associations under this name. Modern practitioners consider it a stone for connecting with spirit guides, enhancing telepathic communication, and promoting compassion. It's often paired with celestite for angelic or spiritual work.
Where It's Found
Primary source of blue gem-quality material
Blue-gray specimens
Classic European anhydrite source
Industrial and specimen-grade material
Price Guide
Good to Know
Scratch test: At hardness 3.5, Angelite can be scratched with a copper coin. Handle gently and keep away from harder stones in your collection.
Sources: Found in 4 notable locations worldwide, from Peru to Poland.
Heft test: Angelite has average mineral density (2.98). It feels about as heavy as you'd expect from a stone its size.
Related Minerals
Similar blue, different chemistry (strontium)
Hydrated form of the same calcium sulfate
Similar color, different mineral (carbonate)
Similar soft blue, much harder (7 Mohs)