What is "gananite"

n. (context mineral English) An isometric-hextetrahedral gray mineral containing bismuth and fluorine.

Gananite is a rare bismuth fluoride mineral with a general formula of BiF. Gananite is an isotropic mineral, it belongs to the space group P43m. This means that Gananite does not show any colors in cross polarized light, because when polarized light passes through it, it does not split into two perpendicular rays. In other words, because Gananite is an isometric mineral, it does not exhibit double refraction. Moreover, this tells us that this mineral is not birefringent. Its color in Plane polarized light is blackish-brown, and it does not show pleochroism.