PYROXMANGITE: Japan (0.55)
Pyroxmangite is a very rare gemstone; grains are seldom clean enough to facet. The material resembles rhodonite and bustamite to a certain degree but can be distinguished on the basis of optic sign and birefringence. Faceted gems are hard to cut because of the cleavages, but once completed they are extremely beautiful and rich in color.
Pyroxmangite Value
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Pyroxmangite Information
| Data | Value |
| Name | Pyroxmangite |
| Crystallography | Triclinic, Crystals tabular; usually massive, in grains. cleavable. |
| Colors | Reddish brown, dark brown, pale to rose pink, purplish pink. The darker colors are due to alteration. |
| Luster | Vitreous to pearly. |
| Hardness | 5.5-6. |
| Density | 3.61-3.80 |
| Birefringence | 0.016—0.020. |
| Cleavage | Perfect 2 directions. Fracture uneven. Brittle. |
| Stone Sizes | Faceted gems are always small since the material is extremely scarce and available only as small transparent grains. Large cabochons could be cut from cleavages and massive material. Collectors should expect to see stones up to about 2 carats. |
| Luminescence | None. |
| Spectral | Not diagnostic. |
| Formula | (Mn,Fe)SiO3. |
| Pleochroism | Slight in shades of pink and red. |
Optics: a=1.726-1.748; β= 1.728-1.750; γ=1.744-1.764.
Biaxial (+), 2V: 35-46°.
Occurrence: In metamorphosed rocks rich in manganese.
Kern County, California; Iva, South Carolina; Boise,Idaho: pale pink.
Broken Hill, New South Wales, Australia: in fine crystals and grains, with rhodonite.
Scotland; Sweden: red-brown.
Finland: brown.
Honshu, Japan: gemmy material.
Comments: Pyroxmangite is a very rare gemstone; grains are seldom clean enough to facet. The material resembles rhodonite and bustamite to a certain degree but can be distinguished on the basis of optic sign and birefringence. Faceted gems are hard to cut because of the cleavages, but once completed they are extremely beautiful and rich in color.
Name: Originally thought to be manganiferous pyroxene, based on studies of the material from South Carolina.
