On the formation of whewellite in the cactaceae species Opuntia microdasys

Abstract

The isolation of well formed crystals of the biomineral whewellite (monohydrated calcium oxalate) from Opuntia microdasys, a cactaceae species found in central Mexico, is described. The morphology of the crystals was investigated by means of electron microscopy. Infrared spectroscopic measurements allow an unambiguous characterization of the nature of the crystals. This is the first report of the presence of a biomineral in this species.