GLENDONITE SPECIMENS

Glendonite is not a mineral, but rather a calcite pseudomorph after ikaite. These mineral formations start out as crystalline masses of ikaite (calcium carbonate hexahydrate) that form in near-freezing, highly alkaline water. At warmer temperatures, ikaite becomes unstable, resulting in the loss of its water content. It then converts to calcite, which retains the ikaite's crystal structure.