About Crystal shapes

Minerals can be identified by the shape of their crystals or crystallography. The shapes of crystals are determined by a number of factors such as the size and length of their surfaces (known as 'faces') and edges, as well as the angles between these. These shapes are named after their geometry - for example, crystals based on cubes belong to the 'cubic or isometric' crystal group. There are seven main crystal groups or systems, as shown here. These are ordered from most symmetrical to lease symmetrical.

Crystal group 1: Cubic (Isometric)

Crystal group 2: Tetragonal

Crystal group 3: Hexagonal

Crystal group 4: Trigonal

Crystal group 5: Orthorhombic

Crystal group 6: Monoclinic

Crystal group 7: Triclinic