Comparison · Sedimentary Rocks
Dolomite vs Dolostone
Dolomite and Dolostone are easy to confuse because both are sedimentary rocks. Both sit near Mohs 3.5–4, 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 Dolomite and Dolostone
- Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Luster is different: Dolomite is vitreous to dull while Dolostone is dull.
- Hold a thin edge to the light: Dolomite is Opaque, Dolostone is opaque.
- They overlap in white, gray, and brown, but Dolomite also comes in pink and yellow.
Dolomite vs Dolostone properties
| Property | Dolomite | Dolostone |
|---|---|---|
| Type | Sedimentary Rocks | Sedimentary Rocks |
| Mohs hardness | 3.5–4 | 3.5 |
| Luster | Vitreous to dull | dull |
| Streak | White | White |
| Transparency | Opaque | opaque |
| Specific gravity | 2.8–2.9 | 2.85 |
| Crystal system | — | varies |
| Common colors | White, Gray, Pink, Brown, Yellow | Tan, Gray, White, Cream, Brown |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $1–$75+ |
Which is more valuable?
Typical specimens of Dolomite and Dolostone trade in a similar range, around $10.
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.
About Dolostone
Dolostone is a carbonate sedimentary rock composed mostly of the mineral dolomite. It often resembles limestone but may react more weakly with dilute acid.
Dolomite vs Dolostone FAQ
Is Dolomite the same as Dolostone?
No. Both are sedimentary rocks, but they are distinct rock types with different hardness, streak or luster. Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Dolomite from Dolostone?
Both sit near Mohs 3.5–4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Luster is different: Dolomite is vitreous to dull while Dolostone is dull. Hold a thin edge to the light: Dolomite is Opaque, Dolostone is opaque.
Which is harder, Dolomite or Dolostone?
They are about equally hard, both near Mohs 3.5–4.
Which is more valuable, Dolomite or Dolostone?
Typical specimens of Dolomite and Dolostone trade in a similar range, around $10.
