Related Links

https://www.nationalgeographic.com/science/earth/inside-the-earth/minerals-gems/

http://www.crystaldictionary.com/

http://www.newadvent.org/cathen/14304c.htm

https://www.crystalvaults.com/crystal-encyclopedia/herkimer-diamond

https://www.yogiapproved.com/health-wellness/healing-crystals-guide/