Sterling Silver Howlite Dyed Turquoise 4mm Knotted Necklace, 36" Gemstones may have been treated to improve their appearance or durability and may require special care Do not use cleaning solvent. Gently wipe with a clean, soft cloth. The natural properties and composition of mined gemstones define the unique beauty of each piece. The image may show slight differences to the actual stone in color and texture