- Boulder opal, total weight: 20.80-carats; blackened diamonds, total weight: 0.82-carats; round brilliant-cut G-H VS1-SI diamonds, total weight: 0.80-carats - Lobster clasp fastening - The black color of these diamonds is the result of an artificial treatment process - This piece is handmade and as such may have some small flecks or scratches - This piece has been certified in accordance with the Hallmarking Act 1973 - NET-A-PORTER is a certified member of the Responsible Jewellery Council