KnowraTrigonal crystal systemLinked fromLinked fromThe 7 pages that link to Trigonal crystal system, each with the reason it gives.All 7Broader topic 2Related 2Compared with 3Crystal systemBroader topic: Its symmetry is distinct, though its lattices are often described using hexagonal axes.TourmalineBroader topic: Tourmaline’s trigonal symmetry governs its elongated crystals and directional physical properties.