Color is green, light blue, blue to blue-green. Luster is vitreous to resinous or greasy. Specimens are transparent to translucent. Crystal Habits include small micromountable prismatic and less often, tabular crystals with a truncation formed by multiple parallel domal and pyramidal faces. Acicular interlocking and radial aggregates are typical.
Individual crystals can display a wide range of crystal faces.
Fracture is uneven. Hardness is 2.5 - 3. Streak is greenish white to bluish-green. Associated Minerals include leadhillite , cerussite , malachite , linarite , brochantite and anglesite . Notable Occurrences include the type locality of Leadhills, Lanarkshire , Scotland as well as the fine specimens from the Mammoth-St Anthony Mine, Tiger, Arizona .