Glossary of Terms

Axis of symmetry

An imaginary line drawn through the center of a crystal that replicates the exact shape if the crystal is turned to 360°. Minerals can have symmetry on their x axis (horizontal symmetry), on their y axis (vertical symmetry), and both their x and y axes. Symmetry can also be calculated on degrees, which depends on how often a Crystal must be rotated to bring out Symmetry (i.e. a hexagon has sixfold symmetry on a 60° angle).