Milarite has a hexagonal crystal system with a prismatic habit. It is not a common mineral, but it is noteworthy from a structural standpoint because it has a double ring structure composed of two 6-member silicate rings that are joined by their apical oxygens.
Highlighting FeaturesPotassium (K) atoms Beryllium (Be) atoms Silicon (Si) atoms Sodium (Na) atoms Yttrium (Y) atoms Oxygen (O) atoms A double silicate ring Single Unit Cell All atoms
Milarite is found in Mexico and Brazil. Gem quality crystals can be found in Namibia.
Hawthorne F C, M. Kimata, P.Cerny, N.Ball, G.R.Rossman, J.D. Grice. 1991. The crystal chemistry of the milarite-group minerals. American Mineralogist 76:1836-1856