Wiktionary
weddellite
n. (context mineralogy English) A mineral form of calcium oxalate.
Wikipedia
Weddellite
Weddellite ( Ca C Oยท2 HO) is a mineral form of calcium oxalate named for occurrences of millimeter-sized crystals found in bottom sediments of the Weddell Sea, off Antarctica. Occasionally, weddellite partially dehydrates to whewellite, forming excellent pseudomorphs of grainy whewellite after weddellite's short tetragonal dipyramids. It was first described in 1942.