In geology, a euhedral is a crystal with well-defined crystal faces. In general, most crystals are composed of many small crystals which are not perfect fit together, and so lack a distinct crystal face. A euhedral crystal is one which is composed of a single crystal lattice, and is recognizable by a large, smooth, flat crystal face.
- Pellant, Chris. The Complete Book of Rocks and Minerals, Dorling Kindersley Inc.: New York (1995), p. 250