you have 
I created this flash and trash but beautiful necklace and earring set using a huge "turquoise" center drop and end drill nuggets, 3 mm garnet beads and sterling silver findings including Bali spacer beads, 4 mm round beads, 3 mm faceted beads, ear wires and a toggle clasp. The huge center drop and nuggets are likely from China. At worst they are dyed white Magnesite or possibliy they are turquoise chalk that has been color shot and combined with a binder. Lots of these stones are being sold in the southwest as real Turquoise, were it so!