Navajo Pearls set in solid sterling silver. The beads are stamped and measure approximately 12mm in size. The length is 16"-18".Perfectly sized for everyday wear! STERLING SILVER NAVAJO PEARLS 16-18" Sterling silver Is an alloy of silver containing 92.5% by weight of silver and 7.5% by weight of other metals. For example, 99.9% pure silver, is relatively soft, so silver is usually alloyed with copper to increase its hardness and strength. Sterling silver is prone to tarnishing, and elements other than copper can be used in alloys to reduce tarnishing. 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 and using a chemical (liver of Sulphur) to treat it to speed up the tarnishing effect.