Sterling Silver Marcasite Green Jade Fortune Drop Box Chain Pendant Necklace, 18" Sterling silver rectangular pendant with Jade and Marcasite . 18" Chain. Jade is commonly treated and impregnated with polymers to enhance its color and improve its stability. Marcasite can appear iridescent in the light. 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. Imported