Here is just a list of gathered tutorials on how to make a gemsona!
(Warning; Both links are on tumblr)
Rebecca Sugar's Tutorial on Arms and Legs
Link 1 This one has pictures and a short description. Be careful; A gem could be more than just the color shown.
Link 2 This one is organized alphabetically. Also, by the name in parenthesis is the type of stone [Ex; Amethyst (Quartz) ]
Link 3 This link orga