Comparison · Minerals
Calcite vs Crocoite
Calcite and Crocoite are easy to confuse because both are minerals. Both sit near Mohs 3, 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 Calcite and Crocoite
- Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Calcite leaves a white streak on unglazed porcelain, Crocoite leaves orange-yellow.
- Crocoite feels noticeably heavier for its size (specific gravity 5.9–6.1 versus 2.7 for Calcite).
- Hold a thin edge to the light: Calcite is transparent, Crocoite is Translucent.
- They overlap in orange, but Calcite also comes in clear, yellow, blue, green, and pink and Crocoite also comes in red.
- Well-formed crystals give it away: Calcite is trigonal, Crocoite is Monoclinic.
Calcite vs Crocoite properties
| Property | Calcite | Crocoite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3 | 2.5–3 |
| Luster | vitreous | Adamantine to vitreous/resinous |
| Streak | White | Orange-yellow |
| Transparency | transparent | Translucent |
| Specific gravity | 2.7 | 5.9–6.1 |
| Crystal system | trigonal | Monoclinic |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | Bright orange-red, Red |
| Rarity | common | common |
| Typical specimen value | $2–$100+ | $2–$150+ |
Which is more valuable?
Crocoite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Crocoite 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 Crocoite
Crocoite is lead chromate, PbCrO4, prized for its vivid orange-red color and slender, elongated prismatic crystals that rank among the most vibrantly colored of any mineral. It forms in the oxidized zones of lead deposits where chromium-bearing solutions interact with lead minerals, a fairly uncommon geochemical pairing. It holds historical significance as the first mineral source of the element chromium, discovered and named in the late 18th century.
Calcite vs Crocoite FAQ
Is Calcite the same as Crocoite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Calcite from Crocoite?
Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Calcite leaves a white streak on unglazed porcelain, Crocoite leaves orange-yellow. Crocoite feels noticeably heavier for its size (specific gravity 5.9–6.1 versus 2.7 for Calcite).
Which is harder, Calcite or Crocoite?
They are about equally hard, both near Mohs 3.
Which is more valuable, Calcite or Crocoite?
Crocoite is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Crocoite can reach $150 or more.
