1ct. Sky Blue Topaz Solitaire Pendant-Necklace in Sterling Silver 18" Chain 1ct Sky Blue Topaz - 6mm Round 18" Sterling Silver Chain included Measures 16mm ( 5/8 inch) .925 Sterling Silver 1 ct Sky Blue Topaz - 6mm Round 18&#034; Sterling Silver Chain included Measures 16mm ( 5/8 inch) .925 Sterling Silver