Wiktionary
rapidcreekite
n. (context mineralogy English) An orthorhombic-dipyramidal mineral containing calcium, carbon, hydrogen, oxygen, and sulfur.
Wikipedia
Rapidcreekite
Rapidcreekite is a rare mineral with formula Ca(SO)(CO)ยท4HO. The mineral is white to colorless and occurs as groupings of acicular (needle-shaped) crystals. It was discovered in 1983 in northern Yukon, Canada, and described in 1986. Rapidcreekite is structurally and compositionally similar to gypsum.