Tsumcorite is yellow-brown, red-brown or orange in color, and it is one of the few minerals that have a yellow streak (orpiment and crocoite are two others). It is translucent, with a vitreous luster, and dichroic yellow to yellow-green.[1][5] The optical class is biaxial and the refractive indices are approximately equal to 1.90.[1][3][5]