Crystalized black zirconium customizable ring core, brushed top and polished comfort interior. 

Flat top with no inlay groove, perfect for ring makers wanting to customize the channel to any requirement. 2.3mm thick and 8mm total width comfort core interior

No need to make the core from scratch, all that's required is  a channel and a little finishing afterwards and these become custom cores.  Unetched / heat treated as rings are easier to machine as such.

Acid etching and heat treating needed to reveal pattern in material, steps below

1- Acid Bath for 1 min or less (Hydrofluoric acid or Multi Etch), dry the rings without touching with hands (use gloves)

2- 650 degrees Celcius in kiln or oven for 15-20 mins to reveal crystal pattern

Sizes 5-13 available