Hi -
About rocks
http://en.wikipedia.org/wiki/Rock_%28geology%29
Rocks/Stones
http://geologywriter.com/blog/stories-in-stone-blog/rock-or-stone-is-there-a-difference/
How Rocks and Stones are Formed
http://www.startlocal.in/articles/educational_articles_how_rocks_are_formed.html
Metaphysical Properties of Stones
https://www.bestcrystals.com/metaphysical.html
Crystals and Gemstones
About Healing Stones
http://www.soularenergy.com/gemstones.htm
Fire Element Gemstones
https://crystal-cure.com/element-fire.html
Psychic Energy by Sun Signs and Elements
http://druidsegg.reformed-druids.org/newslughnasadh10-09.htm
I loved viewing this video. She mentions no need to buy expensive gemstones. Standard stones are just as effective . . .
https://www.youtube.com/watch?v=2StsGzSHsOk