As a very rare mineral, tsumcorite is too easy a mineral to identify. Its distinctive color, uncommon yellow streak and a very high density make it very difficult to mistake. The much more common mimetite , which is associated with tsumcorite, is the only thing close, but has a distinctly different crystal habit. Color is reddish brown to yellowish brown or orange. Luster is vitreous.
Crystals are translucent.
Crystal System is monoclinic. Crystal Habits include platy or prismatic to acicular crystals and radiating fibrous masses and crusts. Cleavage is not observed. Fracture is uneven. Streak is pale yellow.