Comparison · Minerals
Anhydrite vs Celestine
Anhydrite and Celestine are easy to confuse because both are minerals. Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Anhydrite and Celestine
- Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Celestine feels noticeably heavier for its size (specific gravity 3.95–3.97 versus 2.9–3.0 for Anhydrite).
- They overlap in clear, gray, and blue, but Anhydrite also comes in pink and Celestine also comes in green and orange.
Anhydrite vs Celestine properties
| Property | Anhydrite | Celestine |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3–3.5 | 3–3.5 |
| Luster | Vitreous, pearly on cleavage surfaces | Vitreous, pearly on cleavage |
| Streak | White | White |
| Transparency | Transparent to translucent | Transparent to translucent |
| Specific gravity | 2.9–3.0 | 3.95–3.97 |
| Crystal system | Orthorhombic | Orthorhombic |
| Common colors | Colorless, White, Gray, Blue, Pink | Colorless, Pale blue, White, Gray, Light green, Orange (rare) |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Anhydrite and Celestine trade in a similar range, around $20.
About Anhydrite
Anhydrite is calcium sulfate, CaSO4, chemically identical to gypsum but lacking the water molecules bound into gypsum's crystal structure. It forms in evaporite basins where seawater or saline lake water concentrates through evaporation, and it readily absorbs water to convert into gypsum, which is why anhydrite outcrops are less common at the surface than at depth. Its name, from the Greek for "without water," directly references this dehydrated composition.
About Celestine
Celestine, also spelled celestite, is strontium sulfate, SrSO4, and the primary ore of strontium, crystallizing in the orthorhombic system. It is best known for growing in delicate pale blue, tabular crystals, a color that gave the mineral its name from the Latin caelestis, meaning heavenly. Celestine often forms alongside gypsum and calcite in sedimentary evaporite settings, distinguishing it from most other sulfate minerals of hydrothermal origin.
Anhydrite vs Celestine FAQ
Is Anhydrite the same as Celestine?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Anhydrite from Celestine?
Both sit near Mohs 3–3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Celestine feels noticeably heavier for its size (specific gravity 3.95–3.97 versus 2.9–3.0 for Anhydrite). They overlap in clear, gray, and blue, but Anhydrite also comes in pink and Celestine also comes in green and orange.
Which is harder, Anhydrite or Celestine?
They are about equally hard, both near Mohs 3–3.5.
Which is more valuable, Anhydrite or Celestine?
Typical specimens of Anhydrite and Celestine trade in a similar range, around $20.
