The front of this large rhodonite gemstone has been polished to a vitreous lustre. The back of the cabochon is unpolished.
The black markings for which rhodonite is known are caused by manganese oxides.
Discovered in the 17th century, rhodonite is only used for decorative purposes.
Although well-formed crystals do occur, they're extremely rare. Most rhodonite forms in a massive habit, meaning its crystals grow as a tightly intergrown mass with no external shape.
Rhodochrosite
