Crystal Systems: The Geometry of Gems
Understanding the 7 crystal systems and how they help with identification.
Order in Nature
Minerals aren't random; their atoms are arranged in specific, repeating patterns. These internal patterns dictate the external shape of the crystal. There are seven main crystal systems: Isometric (Cubic), Tetragonal, Hexagonal, Trigonal, Orthorhombic, Monoclinic, and Triclinic.
The Cube (Isometric)
The most symmetrical system. Think of a perfect box. Pyrite, garnet, diamond, and spinel fall into this category. They often form cubes, octahedrons (8 faces), or dodecahedrons (12 faces).
Hexagonal & Trigonal
These crystals have a six-sided symmetry. Quartz, aquamarine, and emerald are classic hexagonal/trigonal crystals. They typically form long, six-sided prisms.
Why It Matters
Recognizing the crystal system helps you rule out possibilities. If you find a perfect cube, it can't be quartz (hexagonal). If you find a six-sided prism, it's not a garnet (isometric). It's a powerful identification tool in the field.