Angelite
Anhydrite, calcium sulfate (CaSO4)
A soft pale-blue calcium sulfate, the anhydrous form of gypsum, prized as a gentle, calming tumbled stone.
- Mohs hardness
- 3-3.5
- Color
- soft pale blue to blue-grey, sometimes with white
- Type
- mineral
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Overview
Angelite is the trade name for a soft, pale blue-grey variety of anhydrite (calcium sulfate), the anhydrous cousin of gypsum. Its gentle sky-blue color, often mottled with white veining or reddish flecks, made it popular in the metaphysical market under the "angel stone" name.
Most commercial angelite comes from Peru. It is a relatively soft, opaque stone with a slightly waxy to dull luster, typically sold as tumbled pieces, carved angels, spheres, and beads rather than faceted gems.
Because it is anhydrite, angelite will slowly absorb water and revert toward gypsum if soaked, swelling and crumbling, so it must be kept dry.
Formation & geology
Anhydrite forms primarily in evaporite sedimentary settings, where seawater or saline lake water evaporates and precipitates layered calcium sulfate alongside gypsum, halite, and other salts. It also forms by the dehydration of gypsum when buried under heat and pressure.
The massive blue material sold as angelite occurs in sedimentary basins, with Peru being the dominant source. Anhydrite is also found in salt-dome cap rock and in hydrothermal vein deposits associated with sulfide ores.
Under near-surface conditions anhydrite readily rehydrates back into gypsum, which is why large surface exposures are uncommon and why the stone reacts to water.
How to identify it
Look for a soft, opaque, pale powder-blue stone with a smooth waxy-to-dull luster and frequent white cloudy patches. Hardness is only about 3-3.5, so it scratches easily with a steel knife or even a copper coin.
Its streak is white. Unlike blue calcite, angelite does not fizz in dilute acid (it is a sulfate, not a carbonate). Compared to celestite, angelite is massive and opaque rather than forming sparkling blue crystals.
Key field test: a tiny inconspicuous spot exposed to water will slowly become chalky as the anhydrite begins reverting to gypsum. Look-alikes include howlite (harder veining, usually white), blue calcite (fizzes in acid), and dyed magnesite.
Uses & significance
Angelite is used almost entirely for decorative and metaphysical purposes: tumbled stones, carved angels, palm stones, spheres, and beads. Its softness limits it to protected jewelry such as pendants and earrings rather than rings.
Industrially, anhydrite more broadly is used as a drying agent, a soil conditioner, and a raw material in cement and plaster manufacture, though gem-grade angelite is not used for these.
In crystal-healing traditions it is associated with calm, communication, and "angelic" connection. These claims are spiritual rather than scientific. Practically, the stone's appeal lies in its gentle color and affordability.
Frequently asked questions
Can angelite get wet?
No. Angelite is anhydrite and slowly absorbs water, swelling and crumbling back toward gypsum, so keep it dry and clean it only with a dry or barely damp cloth.
Is angelite the same as celestite?
No. Both are pale blue, but celestite is strontium sulfate that forms sparkling crystals, while angelite is massive, opaque calcium sulfate (anhydrite).
How hard is angelite?
About 3 to 3.5 on the Mohs scale, soft enough to scratch with a knife, so it needs gentle handling.
Where does angelite come from?
Most commercial angelite is mined in Peru, though anhydrite itself occurs in evaporite deposits worldwide.
Angelite guides
In-depth guides for identifying, valuing, and understanding Angelite.
Angelite identified by the community
Real specimens identified with Rock Identifier.
