925 gemstone size 5 ring jewelry

Ring is in good condition and kept in a clean smoke free home. Marked 925 and what looks like ND. If indeed ND I included the brand in the last photo. Size 5 sterling silver ring hase3 hearts filled with gemstone. Tested with my presidium II the black gemstone vines up as tourmaline, the tester only tests several stones so if the composition is similar it may land in this category yet be a different stone. Certain is that it is a stone and is sterling silver. #ring #jewelry #925 #gemstone