The ring had a nice contemporary organic look for sure. Personally, I suspect it was cast in place. That would require the diamond be without serious defects. Casting gemstones in place works well with white diamonds, rubies, blue sapphires and CZs. The burnouts are the key. Slow and low and absolutely no quenching. I do burnouts at 150F degree increment rises sitting at 250F for about 3 hours. Then i continue up to 800F: let it sit there for another couple hours. If i have other flasks that could go to a normal 1200F, i can ramp them up AFTER the cast in place lower temp flasks are out of the kiln. It’s very important to be ready to transfer the flask and get the molten metal into it quickly. I use a lucas centrifuge. The temperature loss because it’s 400F lower than conventional can cause other issues and problems of lif you take too much time in the transfer and casting itself.
I suspect it’s cast in place particularly because of the surface and prongs. They look very naturally like the way a soft sheet green wax would behave. I don’t think the wax was “carved”, but rather “constructed” or built from sheet wax elements merged and melted smooth.
Other gemstones sometimes work with casting info place - but the success is spotty. I did some orange sapphires and hessonite garnets. The garnets fared better. Some of the orange sapphires did survive though. Experiments, you never know what you’re going you get.
Electro forming might work as well, but normally a conductive paint (generally copper) is used and sort of super plated to build up the metal. That process looks more globby to me.
These are a recent medieval inspired design series I’ve been working on. They are sterling with vermeil details (pen plater), and the exterior ring surface from the investment was left in its oxidized state and not polished out. Everything else was carefully polished. The ring body was from a hand carved wax master to emulate a delicate hand peened hammer surface. I had an order for a another couple dozen of another ring that needed that band. I started experimenting with some of those waxes as a good set in place band. They took alot of time, but not anything near the conventional setting approach. Each band with 10 marquise stones has 2 carats total weight.
As a result of the success I bought other gems to try - including natural black spinel 2×4 marquise. Last picture is where this series is going LOL: down the marquise cut gem rabbit hole. . .