Purple Color-changing Stone in Silver Setting on Silver chain

This violet-purple synthetic (man-made/enhanced) stone is multifaceted and throws out lots of color in addition to being varying shades of purple/red-violet depending on the light. (It reminds me of the February birthstone of amethyst, but the color is richer!). Shown next to a penny to show size. Pendant is stamped on back. Necklace measures about 18 inches in length and is stamped "925" (silver) on the clasp. More photos available upon request.