36" Thin Royston & Navajo pearl necklace. sterling silver with varied sized stones and beads from 6mm to 2mm. Easy to layer with other necklaces. STERLING SILVER & ROYSTON TURQUOISE NECKLACE Royston Turquoise: A district in Nevada consisting of three turquoise mines: Bunker Hill, Oscar Wehrend, and the main producer, The Royal Blue. Royston is known for its beautiful colors ranging from deep green to rich, light blues which are set off by a heavy brown matrix.