Identification guide · Carbonates
How to Identify Rhodochrosite
Rhodochrosite is usually pink, rose red, and red with a vitreous luster and is translucent. It has a Mohs hardness of 3.75. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is white. It is most often confused with Calcite, Fluorite, and Red Coral; the tests below separate them.
Rhodochrosite identification checklist
| Color | Pink, Rose red, Red, Orange, Brown | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 3.75 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Perfect rhombohedral | |
| Fracture | Uneven | |
| Specific gravity | 3.65 | Heavier than it looks (specific gravity about 3.65). |
| Crystal system | Trigonal |
Extra tests for Rhodochrosite
Acid test. Fizzes in vinegar or dilute hydrochloric acid because of its carbonate content.
Rhodochrosite look-alikes and how to tell them apart
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Rhodochrosite vs Calcite →
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Rhodochrosite vs Fluorite →
Both sit near Mohs 3.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Rhodochrosite vs Red Coral →
Eudialyte is harder (Mohs 5–5.5) than Rhodochrosite (Mohs 3.75), so Eudialyte will scratch Rhodochrosite and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
Field tips
- Look for rose-pink to red color, either as rhombohedral crystals or banded pink-and-white masses.
- Rhodochrosite is moderately soft, has a perfect rhombohedral cleavage, and effervesces in warm acid.
- Its distinctive pink color and carbonate behavior help separate it from similar minerals.
Rhodochrosite identification FAQ
How can you tell if a rock is Rhodochrosite?
Check the color (pink, rose red, red, and orange), the vitreous luster, a Mohs hardness of 3.75 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Rhodochrosite?
Rhodochrosite has a Mohs hardness of 3.75. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Rhodochrosite and Calcite?
Rhodochrosite (Mohs 3.75, vitreous luster) and Calcite (Mohs 3, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Rhodochrosite vs Calcite comparison for a side-by-side table.
Is Rhodochrosite worth anything?
Entry-level Rhodochrosite specimens sell for around $15, typical collector pieces about $120, and premium examples $900 or more depending on size, quality and locality.
What color is Rhodochrosite?
Rhodochrosite is most often pink, rose red, red, and orange. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
