Sulfates
Angelite
Angelite is the trade name for blue anhydrite, and it comes with a genuinely important care warning most sellers skip over: anhydrite can slowly absorb atmospheric moisture and convert to gypsum over time, a real chemical transformation that can cause a piece to crumble or develop a rough, altered surface if stored in humid conditions.
The geology — what Angelite actually is
- Mineral class
- Sulfate (anhydrous calcium sulfate)
- Chemical formula
- CaSO4
- Crystal system
- Orthorhombic
- Mohs hardness
- 3–3.5
What causes the color: The soft blue color comes from trace strontium or other minor impurities within the calcium sulfate structure, a fairly gentle, pastel coloring compared to more saturated blue minerals like azurite or lapis lazuli.
How it forms: Forms through the dehydration of gypsum deposits, or through direct precipitation from evaporating seawater in arid environments — the reverse transformation (anhydrite absorbing water back into gypsum) is exactly the ongoing process that makes angelite a genuinely delicate long-term storage material.
- Peru (the dominant commercial source of the blue material sold as angelite)
Treatments & imitations: Untreated in the usual sense, though its natural tendency to hydrate into gypsum over time is an inherent property rather than a deliberate treatment; buyers should be told this honestly rather than have it hidden.
Real vs. fake: Genuine angelite shows a soft, slightly translucent blue with a somewhat granular or fibrous texture under magnification, and its Mohs 3–3.5 hardness (easily scratched with a coin) distinguishes it from harder blue imitations like dyed howlite treated to resemble it.
The tradition — how people use Angelite
Historical use: Angelite has no significant ancient documented history under this trade name; anhydrite broadly has industrial uses (as a soil conditioner and in cement production) with a much longer documented record than its ornamental use, which developed as a distinct metaphysical-trade category more recently.
Metaphysical tradition: Modern crystal-healing tradition leans directly into the marketing name itself, associating angelite with angelic communication and higher awareness — an interpretation built almost entirely around the trade name rather than any inherited practice.
How to use it: Carved into small figures, spheres, and cabochons for pendants; because of its softness and moisture sensitivity, it's rarely used in rings that would see frequent water exposure or impact.
Cleansing & care: This is the one stone on this site where water exposure specifically should be minimized long-term, not just handled carefully — angelite (anhydrite) can gradually absorb moisture and convert to gypsum, so store it dry, away from humidity, and skip water cleansing rituals entirely in favor of dry methods.
Frequently asked questions
Why shouldn't angelite get wet?
Angelite is anhydrite, calcium sulfate without water in its structure — and anhydrite can slowly absorb atmospheric or direct moisture and convert into gypsum (a related but different, water-bearing mineral), a real chemical transformation that can cause the stone to crumble or degrade over time if kept in humid or wet conditions.
Related crystals
Celestite
Sulfate Minerals
Celestite gets its name from the Latin caelestis, "heavenly," a reference to its characteristic pale sky-blue color rather than to any ancient religious association — the name was assigned by mineralogists in the 18th century. It's also industrially important well beyond decorative use: celestite is the primary commercial ore of strontium, an element used in everything from ceramic magnets to fireworks (strontium salts produce the red color in many red fireworks).
Blue Aragonite
Carbonates
Blue aragonite is a genuinely uncommon color for a mineral that's usually white, brown, or grey — aragonite is the same calcium carbonate chemistry as ordinary calcite, but its distinct crystal structure and, in this case, a rarer trace-element combination give it a soft sky-blue tone most sellers of white aragonite never encounter.
Howlite
Borate Mineral
Howlite has an unusual claim among stones on this site: in its own natural state it's white-to-grey with dark veining and largely unremarkable, but it has become one of the single most commonly dyed imitation materials in the entire crystal trade, because its porous white structure takes dye exceptionally well and its natural veining pattern can pass for turquoise's matrix or lapis lazuli's calcite veining once colored. First described in 1868 and named for the Canadian geologist Henry How, it carries no ancient tradition of its own — its modern reputation is almost entirely tied to standing in for other, more historically significant stones.
Where to buy Angelite
We don't have an active affiliate program live yet, so instead of a placeholder link, here's the same buying guidance we'd give a friend.
Specialty mineral dealers & gem shows
The most reliable source for anything beyond common tumbled stones — sellers who specialize in minerals tend to disclose treatments and localities unprompted, because their repeat customers ask.
GIA/AGS-affiliated jewelers
For cut gemstones meant for jewelry (not raw specimens), a seller who can produce or reference an independent lab report (GIA, AGS) removes almost all of the real-vs-fake guesswork.
Marketplace sellers with a track record
Etsy and similar marketplaces host genuine small mineral dealers alongside mislabeled resin castings — check seller reviews specifically for photos of received items, not just star ratings.
Local rock & gem shops
Being able to handle a piece before buying lets you apply the weight and hardness checks described on each stone's own page — something no photo can substitute for.
Whichever seller you choose, ask directly whether the stone is natural or synthetic, and whether it's been treated (heated, dyed, irradiated) — a straightforward answer is the single best signal of a trustworthy seller, more useful than any star rating.
Some links on this page are affiliate links — if you buy through them, GemGlow may earn a small commission at no extra cost to you. We only link to sellers we'd genuinely recommend.
Sources and factual basis for the geology above: see our methodology.