Rhodonite’s diagnostic properties are its pink to red color, hardness, high specific gravity, perfect cleavage, and its close association with black manganese oxides. It is sometimes confused with rhodochrosite, which is softer and effervescent in hydrochloric acid, or thulite, which is usually not associated with black manganese oxides. The physical properties of rhodonite are summarized in the table on this page.
| Physical Properties of Rhodonite | |
| Chemical Classification | Silicate |
| Color | Pink, red, reddish brown to brown when weathered |
| Streak | White |
| Luster | Pearly to vitreous |
| Diaphaneity | Transparent to translucent |
| Cleavage | Perfect, two directions, 90 degrees |
| Mohs Hardness | 5.5 to 6.5 |
| Specific Gravity | 3.5 to 3.7 |
| Diagnostic Properties | Pink color, cleavage, specific gravity, frequent association with black manganese oxide |
| Chemical Composition | (Mn2+,Fe2+,Mg,Ca)SiO3 |
| Crystal System | Triclinic |
| Uses | Decorative stone, gemstones |