KnowraTourmalineLinked fromLinked fromThe 5 pages that link to Tourmaline, each with the reason it gives.All 5Broader topic 3Related 2PleochroismBroader topic: Many tourmalines show pronounced pleochroism that affects their appearance when cut.Trigonal crystal systemBroader topic: Its elongated crystals display forms compatible with trigonal symmetry.Rhombohedral crystal systemBroader topic: Its varied compositions share crystal symmetry connected to the rhombohedral system.