Ikranite 1.74 ct.

Ikranite

is a member of the eudialyte group, named after the Shubinov Institute of Crystallography of the Russian Academy of Sciences. It is a cyclosilicate mineral that shows trigonal symmetry with the space group R3m, and is often seen with a pseudo-hexagonal habit. Ikranite appears as translucent and ranges in color from yellow to a brownish yellow. This mineral ranks a 5 on Mohs Scale of Hardness, though it is considered brittle, exhibiting conchoidal fracture when broken.( from Wikipedia) The chemical formula is (Na,H3O)15(Ca,Mn,REE)6Fe+++2Zr3([ ],Zr)([ ],Si)Si24O66(O,OH)6Cl•2-3H2O and is weakly radioactive.

It comes from Kola,Khibiny massif,Mt. Kaskanyunchorr.Rare.

Size: 7.9x7.8x5.5 mm.

Weight: 1.74 ct.

CODE#8626