Comparison · Minerals
Calcite vs Erythrite
Calcite and Erythrite are easy to confuse because both are minerals. Calcite is harder (Mohs 3) than Erythrite (Mohs 1.5–2.5), so Calcite will scratch Erythrite 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 Calcite and Erythrite
- Calcite is harder (Mohs 3) than Erythrite (Mohs 1.5–2.5), so Calcite will scratch Erythrite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
- Streak color differs: Calcite leaves a white streak on unglazed porcelain, Erythrite leaves pale pink to pale red.
- Hold a thin edge to the light: Calcite is transparent, Erythrite is Transparent to translucent.
- They overlap in pink, but Calcite also comes in clear, yellow, orange, blue, and green and Erythrite also comes in red and purple.
- Well-formed crystals give it away: Calcite is trigonal, Erythrite is Monoclinic.
Calcite vs Erythrite properties
| Property | Calcite | Erythrite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3 | 1.5–2.5 |
| Luster | vitreous | Vitreous, pearly on cleavage, silky |
| Streak | White | Pale pink to pale red |
| Transparency | transparent | Transparent to translucent |
| Specific gravity | 2.7 | 3.06–3.18 |
| Crystal system | trigonal | Monoclinic |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | Pink, Crimson red, Purple-red |
| Rarity | common | common |
| Typical specimen value | $2–$100+ | $2–$150+ |
Which is more valuable?
Erythrite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Erythrite can reach $150 or more.
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.
About Erythrite
Erythrite is a hydrous cobalt arsenate, Co3(AsO4)2 8H2O, crystallizing in the monoclinic system with a vivid pink to crimson color that made it a prized prospecting clue. Long nicknamed cobalt bloom or cobalt flower, it forms as a secondary mineral where cobalt-bearing ores have been exposed to oxidizing, weathering conditions. Its bright coloring and soft, often earthy texture make it easy to spot even in small amounts.
Calcite vs Erythrite FAQ
Is Calcite the same as Erythrite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Calcite is harder (Mohs 3) than Erythrite (Mohs 1.5–2.5), so Calcite will scratch Erythrite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Calcite from Erythrite?
Calcite is harder (Mohs 3) than Erythrite (Mohs 1.5–2.5), so Calcite will scratch Erythrite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Streak color differs: Calcite leaves a white streak on unglazed porcelain, Erythrite leaves pale pink to pale red. Hold a thin edge to the light: Calcite is transparent, Erythrite is Transparent to translucent.
Which is harder, Calcite or Erythrite?
Calcite is harder: Mohs 3 against Mohs 1.5–2.5 for Erythrite.
Which is more valuable, Calcite or Erythrite?
Erythrite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Erythrite can reach $150 or more.
