The Gemstone Thulite

Thulite is the pink to reddish variety of the mineral Zoisite. It is an opaque stone composed of dense crystals, and is used as a minor gemstone.


? Red, Pink


? 6 - 6.5

Chemical Formula

? Ca2Al3(SiO4)3(OH)

Mineral Class

? Zoisite

Additional Properties

Crystal System
? Orthorhombic
Refractive Index
? 1.69 - 1.70
Double Refraction
? .009
? Opaque. May be translucent in thin backlit sections.
? 3.2 - 3.4
? Vitreous
Cleavage ? 1,1

All About

Thulite is well-known in Norway, where it was first found. It is named after the mythical region of Thule, which many identify with Norway. The color of Thulite is caused by the element manganese in its composition. Thulite often occurs associated with Quartz, and is sometimes mottled with streaks or spots of white Quartz.

Clinothulite is pink, manganese-rich variety of the mineral Clinozoisite. Zoisite and Clinozoisite are very similar minerals, differing only in crystal structure. This makes Thulite and Clinothulite almost identical, and sometimes it is impossible to make a distinction without complex tests.


? Thulite is an inexpensive gemstone. It is cut into cabochon and beads, and carved into ornamental objects.

Other Names


Treatments & Enhancements

? Thulite is not treated or enhanced.

Thulite Sources

? The primary source of Thulite is from Norway at Tvedestrand and Leksvik in Sorlandet, Aust-Auger. Thulite also comes from the U.S. at North Carolina.

Similar Gemstones

? Thulite is most similar to Rhodonite, though it usually lacks the black streaks often present in Rhodonite. Thulite also lacks the banding of Rhodochrosite and is harder.

Thulite in the Rough Photos



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