Turquoise, like tigereye and goldstone is fairly easy to pick out of a crowd - on the surface.  The color is easy enough to find but determining whether something is truly turquoise-stone is something else.  Most of what I've used thus far is either dyed howlite or dyed and treated chalk turquoise, which some consider to be a form of fakery.  I'll let the quality of the jewelry speak for itself and let you decide.