We know but little of this rare mineral, but an idea may be obtained of it from the figure, sufficient for impressing the name upon the memory. The following characters may also be of service in recognizing it when met with. Its structure is compact foliated with laminae in two directions, parallel to the sides of an acute rhomboidal prism; the cross fracture is hackly and shining; it is hard enough to scratch glass strongly and is rather brittle; the most perfect parts are semitransparcnt and of a deep pink colour, other parts are paler by degrees until they are nearly white or yellowish white and opaque. Before the blowpipe the transparent parts soon become opaque and if the heat be suddenly raised, it intumesces much and produces a dull infusible spongy light brown slag.

The minerals that accompany Thulite arc verdigrease, green Idocrase, Lilac Fluor, and Quartz. It is found in Souland, in Telemarken, Norway, and also in Greenland.

The specimen figured is in Mr. Hculands collection, it is from Norway.