Tantalum will anodize exactly as does titanium, but it gives a much
more beautiful color effect. Same colors, but much more vivid than
(it’s a visual effect, so I can’t explain it in a way that’ll make
sense, but do a color test strip with Ta, and then another one with
Ti. Lay them side by side, and you’ll see the difference I’m talking
Unfortunately, neither metal does “black” well, unless you burn
them, which is likely to make them brittle.
On both metals, the color is a surface effect that’s reasonably
fragile, and certainly not something I’d use for the hard wearing
section of a wedding ring.
I’d look more at either tungsten carbide, or black ceramic for
something like that.
For whatever that’s worth,