Luster is adamantine. Crystals are transparent to translucent. Crystal Habits include small octahedral crystals. Hardness is 4. Streak is bright yellow.
Specimens are slightly radioactive.
Associated Minerals include tellurium and other tellurates and tellurites . Notable Occurrences are limited to the type locality of San Miguel Mine, Moctezuma, Sonora, Mexico . Best Field Indicators are locality,softness, high density, luster, radioactivity and cleavage.