Comparison · Minerals
Aurichalcite vs Calcite
Aurichalcite and Calcite are easy to confuse because both are minerals. Calcite is harder (Mohs 3) than Aurichalcite (Mohs 1–2), so Calcite will scratch Aurichalcite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Aurichalcite and Calcite
- Calcite is harder (Mohs 3) than Aurichalcite (Mohs 1–2), so Calcite will scratch Aurichalcite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
- Streak color differs: Aurichalcite leaves a pale blue-green streak on unglazed porcelain, Calcite leaves white.
- Luster is different: Aurichalcite is silky, pearly while Calcite is vitreous.
- Aurichalcite feels noticeably heavier for its size (specific gravity 3.6–3.9 versus 2.7 for Calcite).
- Hold a thin edge to the light: Aurichalcite is Translucent, Calcite is transparent.
- They overlap in green and blue, but Calcite also comes in clear, yellow, orange, and pink.
- Well-formed crystals give it away: Aurichalcite is Monoclinic, Calcite is trigonal.
Aurichalcite vs Calcite properties
| Property | Aurichalcite | Calcite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 1–2 | 3 |
| Luster | Silky, pearly | vitreous |
| Streak | Pale blue-green | White |
| Transparency | Translucent | transparent |
| Specific gravity | 3.6–3.9 | 2.7 |
| Crystal system | Monoclinic | trigonal |
| Common colors | Pale green, Blue-green, Sky blue | Colorless, White, Yellow, Orange, Blue, Green, Pink |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$100+ |
Which is more valuable?
Aurichalcite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Aurichalcite can reach $150 or more.
About Aurichalcite
Aurichalcite is a hydrated zinc copper carbonate, (Zn,Cu)5(CO3)2(OH)6, that forms as a secondary mineral in the weathered, oxidized portions of zinc and copper ore bodies. It typically appears as delicate, pale blue-green sprays of needle-like crystals with a distinctly pearly luster. The name derives from Greek words for gold and copper, an old and somewhat misleading reference to brass-like alloys rather than the mineral's actual color.
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.
Aurichalcite vs Calcite FAQ
Is Aurichalcite the same as Calcite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Calcite is harder (Mohs 3) than Aurichalcite (Mohs 1–2), so Calcite will scratch Aurichalcite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Aurichalcite from Calcite?
Calcite is harder (Mohs 3) than Aurichalcite (Mohs 1–2), so Calcite will scratch Aurichalcite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Streak color differs: Aurichalcite leaves a pale blue-green streak on unglazed porcelain, Calcite leaves white. Luster is different: Aurichalcite is silky, pearly while Calcite is vitreous.
Which is harder, Aurichalcite or Calcite?
Calcite is harder: Mohs 3 against Mohs 1–2 for Aurichalcite.
Which is more valuable, Aurichalcite or Calcite?
Aurichalcite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Aurichalcite can reach $150 or more.
