Color varies from colorless to white and pinkish yellow. Luster is vitreous to resinous. Diaphaneity is transparent to translucent.
Fracture is subconchoidal.
Streak is uncolored. Associated Minerals include analcime, calcite, dolomite, natrolite, polylithionite, pyrite and siderite. Named in 1790 after the original locality in Aragon, Spain.