NEPHELINE SYENITE SPHERE
This is the polished nepheline syenite sphere. Diameter 2.5″ (63mm). Weight – 12.6oz (357 grams). Origin: Russia, Kola Peninsula.
Some information about nepheline syenite:
Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are also known.
The chemical peculiarities of the nepheline-syenites are well marked. They are exceedingly rich in alkalis and in alumina with silica varying from 50 to 56%, while lime, magnesia and iron are never present in great quantity, though somewhat more variable than the other components.
Nepheline syenites occur in Russia (Kola Peninsula; the Ural Mountains), Canada, Norway, Greenland, Sweden, the Pyrenees, Italy, Brazil, China, the Transvaal region, the mountains of the Central Montana Alkali Province, and Magnet Cove igneous complex of Arkansas, as well as on oceanic islands.