The slightly larger one is made in four pieces, the bowl, the stem and two pieces in the base laminated. The metal is sterling silver, the ring being planted on a rebate at the top of the stem, the base being laminated with the silver between. It was then carefully scalloped - with a 4.8mm chainsaw chain file. After finishing the base with 1000 wet and dry it was all glued up.
The other was a little more difficult. I made a silver (wire) ring, then made a shallow groove the same size in the end of the cylindrical blank. I then filed the ring into a horizontal D section and epoxied it into the groove. The bowl was turned with the silver already in place to guarantee concentricity. I then made the silver base ring, which filed out to a D section (as a wedding ring). I then turned the bottom of the blank into a very shallow taper, and coated it with epoxy, sliding the ring up it until it sat tightly. When this was dry, I turned in through it for the base. When finished I parted it off, leaving very little waste as the blank was glued to a 2" long 1" diameter waste piece in the chuck.
Sorry, a little off tack for this thread - I just put it in as an example of small bits of blackwood, and to show how it can just be waxed.