Haven't been to the worshop lately, except to pack, as I am in the process of moving to a place with cheaper rent and closer to home.
But I have not been completely inactive.
Here is an engagement ring (yes, you guessed right) with a top quality 0.12 carat diamond set in a cast 25% shibuichi ring. The gray of the shibuichi is much better at bringing out the white light of the diamond instead of the usual white metals, silver and platinum, in my opinion at least.
The ring was cast, so that after patination no seam line would be visible, and the stone was set by a professional, then the whole thing patinated with Baldwin's patina and rubbed with Rennaisance wax.
It might have looked even better in black shakudo... but I'm saving that for the actual wedding rings ;-)