Can I get a custom ring made with both gold and platinum?

Short answer: yes. Longer answer: it depends on what you mean by "both" and how much you hate your future jeweler. I've made rings that combine gold and platinum maybe two dozen times over twenty-two years, and each one required a different approach depending on where each metal ends up.

The most common setup is a platinum head or basket with a gold shank. The head holds the stone - you want platinum there because it's harder than 14k or even 18k gold, and prongs that wear thin mean a stone you might lose. The shank - the band that goes around your finger - is 18k yellow or rose gold, because gold has better spring memory than platinum and won't oval out as fast on a daily-wear ring. It's also dramatically cheaper. A typical engagement ring with a platinum head and an 18k gold shank runs about 30-40% less than a full platinum ring, and in my opinion it's the better engineering choice for most clients.

The trick is the junction. You can't just solder platinum to gold and call it a day. The melting points are different - platinum fires around 1770°C, gold around 1060°C - so you're either laser welding the seam or using a palladium-based solder that bridges the gap. I laser weld. A client named Marco came in last spring wanting a platinum bezel on a rose gold band, and we welded the bezel directly to a recessed seat in the shank. The seam is invisible unless you know where to look.

Less common combos that work

I've done a two-tone band - platinum on the outside edges, rose gold in the center channel - by fabricating three separate strips and welding them together before forming the ring. That's about $400 in labor you wouldn't have with a single metal, and it limits resizing to maybe one full size because the weld seam changes the metal's behavior.

I've also done a platinum shank with gold prongs. That one I don't recommend. Gold prongs wear faster than platinum, and if you're already paying for a platinum shank, you're better off spending the extra hundred or two for platinum prongs. The color difference is negligible under a stone.

What won't work

You cannot cast a ring in both metals at once. They don't alloy. You can't electroform them together either. Every combination is a joining operation - welding, soldering, or mechanical interlock (like a tension setting that traps one metal inside the other, which I've done exactly once and will not do again).

And resizing? If the ring is half platinum, half gold, and it needs to go up or down more than a quarter size, you're looking at a partial remake. I tell every client who wants the combo: if your fingers change size significantly, you're buying a new ring, not resizing this one.

Cost and timeline

For a platinum head on an 18k gold shank, add about $300-500 in fabrication time and about two weeks to the typical six-to-ten-week custom timeline. For anything more complicated - patterned bands, inlaid metals, mixed-metal pavé - plan on $800-1,200 in extra labor and a minimum of ten weeks. I had a client named Priya who wanted a platinum milgrain edge on an 18k yellow band. That was hand-graved after assembly, and it took three weeks just for the milgrain.

So yes, you can do it. Just know what you're signing up for.