Thulite is a massive pink variety of zoisite, It gets its reddish-to-pink coloring from the inclusion of manganese. It is sometimes carved or formed into cabochons. Confusion with rhodonite is possible.
Other varieties of zoisite are tanzanite and ruby-in-zoisite (anyolite).
Gemological Information for Thulite
| Color: | Pink (Sometimes with White Streaks) |
| Crystal Structure: | Orthorhombic |
| Refractive Index: | 1.691 to 1.700 |
| Durability: | Fair to Poor |
| Hardness: | Fair to Poor |
| Family: | Zoisite |
| Similar Stones: | Rhodonite, Hydrogrossular Garnet |
| Treatments: | None Known |
| Country of Origin: | Tanzania, Austria, Germany, Italy, Mexico, Switzerland, U.S. |
Thulite Care
| Ultrasonic Cleaning: | Never |
| Steam Cleaning: | Never |
| Warm Soapy Water: | Safe |
| Chemical Attack: | Hydrochloric and Hydrofluoric Acids Attack |
| Light Sensitivity: | Stable |
| Heat Sensitivity: | Jeweler's Torch May Fuse |
Sources
- Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 262-264.
- Schumann, Walter. Gemstones of the World, New York: Sterling Publishing, Co., 1977. Pp. 160.