Calcite pseudomorph after Ikaite

Ikaite has the chemical formula CaCO3 · 6H2O. The water evaporates at 8°C leaving behind a calcite (CaCO3) pseudomorph with the ikaite shape (and holes due to loss of mass during the evaporation/pseudomorphosis). Here are large and small glendonite crystals making a very sculptural and aesthetic specimen. These are found at the Olenitsa River in Russia and are world famous for their appearance and orange color.