 Zigrasite exhibits imperfect cleavage in two directions, parallel to (010) and (001), it shows no parting, is brittle and has hackly fracture.In transmitted light zigrasite is colorless and non-pleochroic, biaxial negative with indices of refraction α 1.597(1) β 1.622 (1), γ 1.635 (1).Zigrasite is translucent and shows a light blue to pale yellow cathodoluminescence.