The noun crystal is a singular, common, concrete noun; a Word for:
- a quartz that is transparent;
- a solid form of a substance or mixture that has a regularly repeating internal arrangement of its atoms and often external plane faces;
- the transparent cover over a watch or clock dial;
- an uncountable noun as a Word for a clear colorless glass of very good quality; a countable noun for things made of this glass.
The Word crystal is also an adjective, used to describe a noun.
