HARDCOPY SOURCES
Love is in the Earth - A Kaleidoscope of Crystals Updated |by MELODY| LCCC# 94-061710 | ISBN: 0-9628190-3-4 | Copyright 1995 by Earth Love Publishing House
Cunningham's Encyclopedia of Crystal, Gem & Metal Magic | by Scott Cunningham | LCCC# 87-46256 | ISBN: 0-87542-126-1 | Copyright 2003 by Scott Cunningham
I highly recommend both of these books for anyone interested in the metaphysical and physical characteristics of stones!
ONLINE SOURCES
CRYSTALPEDIA - https://mycrystalpedia.wordpress.com/
PERSONAL SOURCES
My own personal observations and experiences working with these stones, crystals and metals.