Stewartite is named for the Stewart Mine, Pala, San Diego County, California where the mineral was first described. Luster is vitreous. Specimens are translucent to transparent. Crystal System is triclinic. Crystal Habits include wedge-shaped to tabular or prismatic crystals and fibrous crusts.
Cleavage is perfect.
Fracture is conchoidal. Streak is white. Associated Minerals include strunzite , stewartite and limonite and others. Best Field Indicators are color, locality, crystal habit, associations and perfect cleavage.