Aquamarine 6mm matched, translucent natural clean gemstones (origin Brazil), excellent sea-blue colour. Aquamarine belongs to the same crystal family as Emerald, namely the Beryl crystal family, and can be as heavily included as its Emerald cousin, but unlike Emerald, Aquamarine can often enough be found in cut gemstones free of eye-visible inclusions, as are the above Aquamarine 6mm round cut gemstones.
Blue Topaz can be confused with Aquamarine, but there is a clarity of blue, a coolness almost, in fine Aquamarine that Blue Topaz does not exhibit.

Note the solidity of the 9ct Gold Sydney-crafted settings. Two of the above image gallery, one showing side, the other rear, indicate that solidity.
The term “classic design” used to describe the style of these settings, consisting of a setting edge sitting slightly proud in a frame, refers to its use over many, many centuries, at least as far back as the Ancient Roman period.