Rhodochrosite derives its pink color from manganese. Gem-quality crystals do occur, and are cut for collectors, but the fine-grained, banded rock is more commonly used for decoration.

Rhodochrosite occurs in veins associated with manganese, copper, silver, and lead deposits. Argentina has the oldest mines, and banded rhodochrosite from there is sometimes called Inca rose. Today, the prime commercial sources are in United States.

Chemical Composition: 

Manganese Carbonate - MnCO₃

Colors / Varieties: 

• Banded variety (translucent to opaque): Pink, white, grey, brown.
• Transparent: Pink, red, orange-red

Crystal System / Forms: 

Trigonal System / Rhombohedral crystals, massive aggregates.

Hardness: 

4

Specific Gravity: 

3.50 - 3.70

Cleavage / Fracture: 

3 directional cleavage but not seen due to aggregate / Uneven fracture.

Optic Character: 

Anisotropic, D.R.; Uniaxial negative

Lustre: 

Sub-vitreous

Refractive Index / Birefringence: 

1.600 - 1.820 / 0.220. A diffused spot R.I. reading in aggregates.

Pleochroism: 

None.

Magnification: 

Banding in aggregates

U.V. Fluorescence: 

Varying with most showing a weak red fluorescence under ultra violet lamp.

Spectrum: 

Band centered at 551nm

Cause of Color: 

Manganese

Specific Tests: 

Effervesces with acid.

Simulants (with separation tests): 

Rhodonite (structure, birefringence), Chalcedony (R.I., S.G., birefringence), Hydrogrossular Garnet (birefringence, structure

Geological Occurrence: 

As a secondary mineral in manganese ore deposits, as granular masses and in hydrothermal veins.

Sources: 

Argentina, U.S.A., Romania, Hungary, South Africa.

Cuts & Uses: 

Facetted cuts, cabochon, beads, etc.