Comparison · Minerals vs Phosphate Minerals
Calcite vs Vivianite
Calcite and Vivianite are easy to confuse. Calcite is harder (Mohs 3) than Vivianite (Mohs 1.75), so Calcite will scratch Vivianite 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 Vivianite
- Calcite is harder (Mohs 3) than Vivianite (Mohs 1.75), so Calcite will scratch Vivianite 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, Vivianite leaves bluish white.
- Hold a thin edge to the light: Calcite is transparent, Vivianite is translucent.
- They overlap in clear, blue, and green, but Calcite also comes in yellow, orange, and pink.
- Well-formed crystals give it away: Calcite is trigonal, Vivianite is monoclinic.
Calcite vs Vivianite properties
| Property | Calcite | Vivianite |
|---|---|---|
| Type | Minerals | Phosphate Minerals |
| Mohs hardness | 3 | 1.75 |
| Luster | vitreous | vitreous |
| Streak | White | Bluish white |
| Transparency | transparent | translucent |
| Specific gravity | 2.7 | 2.68 |
| Crystal system | trigonal | monoclinic |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | Blue, Green, Colorless |
| Rarity | common | uncommon |
| Typical specimen value | $2–$100+ | $10–$400+ |
Which is more valuable?
Vivianite is usually the more valuable of the two: a typical collector specimen runs about $60 against $15 for Calcite, and premium Vivianite can reach $400 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 Vivianite
Vivianite is a hydrated iron phosphate that is colorless when fresh but oxidizes to deep blue and green. It forms bladed, prismatic, or fibrous crystals and earthy masses, and is a favorite of collectors for its rich color.
Calcite vs Vivianite FAQ
Is Calcite the same as Vivianite?
No. Calcite is a mineral while Vivianite is a phosphate mineral. Calcite is harder (Mohs 3) than Vivianite (Mohs 1.75), so Calcite will scratch Vivianite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Calcite from Vivianite?
Calcite is harder (Mohs 3) than Vivianite (Mohs 1.75), so Calcite will scratch Vivianite 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, Vivianite leaves bluish white. Hold a thin edge to the light: Calcite is transparent, Vivianite is translucent.
Which is harder, Calcite or Vivianite?
Calcite is harder: Mohs 3 against Mohs 1.75 for Vivianite.
Which is more valuable, Calcite or Vivianite?
Vivianite is usually the more valuable of the two: a typical collector specimen runs about $60 against $15 for Calcite, and premium Vivianite can reach $400 or more.
