wattevilleite

\\ˈwätviˌlīt\ noun (-s)

Usage: usually capitalized

Etymology: German wattevillit, from Baron Oscar de Watteville, 19th century Frenchman + German -it -ite

: a mineral Na₂Ca(SO₄)₂.4H₂O(?) that is a hydrous sulfate of sodium and calcium and occurs as aggregates of minute hairlike crystals