(Rhombohedral System) - Axes and angles in this system are similar to the Hexagonal System, and the two systems are often combined as Hexagonal. In the cross-section of a Hexagonal crystal, there will be six sides. In the cross-section of a Trigonal crystal there will be three sides.
Based on a triangular inner structure.
Crystal shapes:
- Three-sided prisms or pyramids
- Rhombohedra
- Scalenohedra
Some Trigonal Crystals:
- Agate
- Amethyst
- Aventurine
- Calcite
- Carnelian
- Citrine
- Hematite
- Jasper
- Phenakite
- Quartz
- Rhodochrosite
- Rose Quartz
- Ruby, Sapphire
- Smoky Quartz
- Tigers Eye
- Tourmaline
8 products














































































