Aura by 925 TJM SS 6.75 cttw Black Onyx & 0.38 cttw Marcasite Pendant with 18" chain Silver Jewelry with gemstones Bold Square Shape Pendant Set With Black Onyx & Marcasite 18" 925 sterling silver metal Product Dimension: 26.41mm x 17.91mm x 7.54mm Product Weight: 10.74 grams Sterling silver jewelry made with great quality marcasite