Ekanite

Most Ekanite comes from Sri Lanka, but deposits have also been found in Canada and Russia. Gem quality Ekanite is relatively uncommon. As a rule, Ekanite gemstones are green but there are also yellow and red varieties.

Chemically, it is ThCa2Si8O20  (by weight, approximately 30% thorium). On the Moh's hardness scale it ranks 6 to 6.5. 

The rather noticeable radioactivity of the stone is due to its thorium content. Over time, the Ekanite will deteriorate as a result of the damage caused to the crystalline lattice by the alpha emissions.

Size: 5.1  x  4.5 mm

Weight: 0.12 grams;  0.6 ct.

Activity:  ca. 3,000 pCi  (100 Bq) of Th-232 with all the members of the decay series in secular equilibrium.

                 ca. 1,200 cpm above background with a pancake GM.

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Last updated: 05/10/11
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