A crystal consists of matter that is formed from an ordered arrangement of atoms, molecules, or ions. At the macroscopic scale crystals have well defined shapes with flat faces. Examples of crystals are snowflakes, diamonds, and quartz.
For tagging purposes this tag is to be used for objects that are generally composed of translucent material and whose surface is composed of facets (flat surfaces).
If it has been cut in an organized manner, particularly like that used for jewelry, then the diamond_(gemstone) tag should also be included.
If the object is rounded and features no edges between surfaces, then the object should be tagged gem instead.
For the Nuclear Throne character see crystal (nuclear throne).