Sterling silver adjustable collar. A oval piece of Golden Hill's turquoise dangles from the center.The silver beads measure from approximately 9mm to 3mm. Easy to wear and very comfortable. BEADED ADJUSTABLE COLLAR WITH TURQUOISE Oxidized silver (black coloring in the silver) is a process that many jewelers use to give sterling silver a black patina. It gives the jewelry an antique or tarnished look. The process consists of taking clean Sterling silver Is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals, usually copper the sterling silver has a minimum fineness of. 925 In the Russian hills of Kazakhstan sits the GOLDEN HILLS mine. The Turquoise is only mined in the winter months during the freezing cold and snow as rains flood the mine during the summer. The location of the mine is remote and difficult to bring equipment in and out of. It is the only Turquoise known to have the unique coloring of bright blue with a Lavender undertone. Special stone available this year is Kazakhstan Turquoise, or Golden Hills Turquoise. A rare color for turquoise, Golden Hills Turquoise comes from a deposit in the Altyn Tyube mine in Kazakhstan. These stunning gems have a light blue hue to them, and a reddish, burnt umber matrix. The Golden Hills mine is known for producing large quantities of dioptase, a gem very similar to turquoise in color and strength, mimicking emerald in its magnificent green color. The turquoise deposit was found most recently 2013 and was most notably featured at the Tucson Gem and Jewelry show in January of 2014.