Hafnon occurs as transparent red to red orange tetragonal crystals with a hardness of 7.5.

It belongs to the spinel group and forms tetragonal crystals.

Braunite forms grey/black tetragonal crystals and has a Mohs hardness of 6 - 6.5.

It has varieties with tetragonal, orthorhombic or triclinic crystals.

The tetragonal crystals are hemihedral with parallel faces (like scheelite), and at times of considerable size.

It occurs massive and in tetragonal crystals of a bright brass yellow color.

The salt crystallizes as tetragonal crystals.

It forms tetragonal crystals with perfect 001 cleavage.

It is a white solid with a tetragonal crystal structure.

Its tetragonal crystals are a translucent blue, white, colorless or pink with a vitreous to dull lustre.