Length: 17.75 inches; Deep: 0.5 inches; Clasp: Hook. SKU: n20582; Weight: 13.8g; Stone: genuine tourmaline beads; Material: Genuine Sterling Silver (925 silver, 92.5% silver content); Stamp: 925; Tourmaline is a coveted stone that comes in a wide range of colors from black to pink, green and blue. Crystals which display more than one color together are common. A cross-section of a watermelon tourmaline crystal reveals green on the outside and pink within.