It looks black, but in transmitted light are actually a deep yellow. The crystals are approximately 3mm in 8-9mm groups. These are unique "curled" crystals.
Descloizite
Formula
PbZnVO4(OH)
Crystal System
Orthorhombic
Crystal Habit
Plumose, Tabular, Encrustations
Cleavage
None, None, None
Luster
Greasy (Oily)
Color
dark brownish black, dark reddish brown, orange red, reddish brown, black