Crystal forms
Sources
https://en.wikipedia.org/wiki/Cubic_crystal_system
https://www.gemstone7.com/562-hexagonal-quartz.html
https://en.wikipedia.org/wiki/Monoclinic_crystal_system
https://www.britannica.com/science/orthorhombic-system
https://en.wikipedia.org/wiki/Tetragonal_crystal_system
https://en.wikipedia.org/wiki/Triclinic_crystal_system
http://www.geologyin.com/2014/11/crystal-structure-and-crystal-system.html
