Crystals are translucent to more rarely transparent. Crystal System is trigonal. Crystal Habits include small acicular, platy or thin tabular crystals that form rosettes. Also known to form double hexagonal pyramids and rhombohedrons. Often intergrown in a lamellar fashion with synchysite, rontgenite and bastnasite.
Fracture is subconchoidal to splintery.
Hardness is typically around 4.5 but will vary from 4 to 5. Streak is white to yellowish white. Notable Occurrences include the type locality in the Muzo emerald deposit in the Muzo district, Bogota, Colombia.