1) Barium mineral 
Macdonaldite is a rare barium silicate mineral with a chemical formula of BaCa4Si16O36(OH)2·10H2O. Macdonaldite was first described in 1965 and named for Gordon Andrew Macdonald (1911–1978) an American volcanologist at the University of Hawaii. Macdonaldite crystallises in the orthorhombic system. Macdonaldite is anisotropic with low relief. Ma...