18ct white gold 186ct aquamarine 024 diamond halo cluster ringcrwshrd8aq the aquamarine collection by tivon features the celebrated aquamarine stone known for its stunning range of light sky blue colours to deep sea blue shades according to legends this magical gem originated in the treasure chests of mermaids and has since been regarded as the sailors lucky stone this enchanting tivon aquamarine ring boasts a stunning 186 carat tanzanite stone set onto a classic 18 carat white gold ban