Comparison · Minerals vs Sedimentary Rocks
Calcite vs Dolomite
Calcite and Dolomite are easy to confuse. 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 Dolomite
- Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Calcite is transparent, Dolomite is Opaque.
- They overlap in yellow and pink, but Calcite also comes in clear, orange, blue, and green and Dolomite also comes in white, gray, and brown.
Calcite vs Dolomite properties
| Property | Calcite | Dolomite |
|---|---|---|
| Type | Minerals | Sedimentary Rocks |
| Mohs hardness | 3 | 3.5–4 |
| Luster | vitreous | Vitreous to dull |
| Streak | White | White |
| Transparency | transparent | Opaque |
| Specific gravity | 2.7 | 2.8–2.9 |
| Crystal system | trigonal | — |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | White, Gray, Pink, Brown, Yellow |
| Rarity | common | common |
| Typical specimen value | $2–$100+ | $1–$75+ |
Which is more valuable?
Calcite is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Dolomite, and premium Calcite can reach $100 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 Dolomite
Dolomite refers both to the mineral calcium magnesium carbonate, CaMg(CO3)2, and to dolostone, the sedimentary rock composed largely of that mineral. Dolostone typically forms when magnesium-rich water alters existing limestone after deposition, replacing some of the original calcium with magnesium in a process still actively studied by geologists. The rock is usually pale gray, tan, or pinkish and weathers into rounded, pitted outcrops distinct from sharper limestone cliffs.
Calcite vs Dolomite FAQ
Is Calcite the same as Dolomite?
No. Calcite is a mineral while Dolomite is a sedimentary rock. 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 Dolomite?
Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Calcite is transparent, Dolomite is Opaque. They overlap in yellow and pink, but Calcite also comes in clear, orange, blue, and green and Dolomite also comes in white, gray, and brown.
Which is harder, Calcite or Dolomite?
Dolomite is harder: Mohs 3.5–4 against Mohs 3 for Calcite.
Which is more valuable, Calcite or Dolomite?
Calcite is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Dolomite, and premium Calcite can reach $100 or more.
