Comparison · Minerals
Apophyllite vs Calcite
Apophyllite and Calcite are easy to confuse because both are minerals. Apophyllite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Apophyllite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Apophyllite and Calcite
- Apophyllite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Apophyllite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
- Hold a thin edge to the light: Apophyllite is Transparent to translucent, Calcite is transparent.
- They overlap in clear, green, pink, and yellow, but Calcite also comes in orange and blue.
- Well-formed crystals give it away: Apophyllite is Tetragonal, Calcite is trigonal.
Apophyllite vs Calcite properties
| Property | Apophyllite | Calcite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 4.5–5 | 3 |
| Luster | Vitreous, pearly on cleavage | vitreous |
| Streak | White | White |
| Transparency | Transparent to translucent | transparent |
| Specific gravity | 2.3–2.4 | 2.7 |
| Crystal system | Tetragonal | trigonal |
| Common colors | Colorless, White, Green, Pink, Pale yellow | Colorless, White, Yellow, Orange, Blue, Green, Pink |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$100+ |
Which is more valuable?
Apophyllite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Apophyllite can reach $150 or more.
About Apophyllite
Apophyllite is the common name for a small group of hydrated potassium calcium silicates, most often KCa4Si8O20(F,OH)·8H2O, crystallizing in the tetragonal system. It typically grows as glassy, pseudo-cubic or pyramidal crystals lining cavities in basaltic lava. The name comes from the Greek for 'to leaf away,' describing how the mineral flakes when heated, losing its water of crystallization.
About Calcite
Calcite is one of the most common minerals on Earth, found in sedimentary, metamorphic, and igneous rocks. It's the primary component of limestone and marble.
Apophyllite vs Calcite FAQ
Is Apophyllite the same as Calcite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Apophyllite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Apophyllite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
How can you tell Apophyllite from Calcite?
Apophyllite is harder (Mohs 4.5–5) than Calcite (Mohs 3), so Apophyllite will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Hold a thin edge to the light: Apophyllite is Transparent to translucent, Calcite is transparent. They overlap in clear, green, pink, and yellow, but Calcite also comes in orange and blue.
Which is harder, Apophyllite or Calcite?
Apophyllite is harder: Mohs 4.5–5 against Mohs 3 for Calcite.
Which is more valuable, Apophyllite or Calcite?
Apophyllite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Apophyllite can reach $150 or more.
