Natural "Fancy Cut" Carbonado Solitaire Engagement Ring 14k Yellow Gold Wedding Ring byAngeline Ring. This ring is available here this one is a size 7 and it can be resized. I created a rustic texture in the solid 14k yellow gold. The stone measures about 10mm X 8mm (3.27 carats). 

(From https://www.gemsociety.org/article/black-diamonds/ <-- read more about Carbonados here )

"Carbonado might have an extraterrestrial origin, which could account for some of its unusual properties. Unlike diamonds, carbonados are never found in igneous kimberlite rock formed deep within the earth but in alluvial, sedimentary deposits instead. The micro-diamonds present in carbonado (typically smaller than 20 microns or 20 millionths of a meter) lack traces of minerals found deep in the Earth’s mantle, typical of other diamonds, but do possess traces of nitrogen, hydrogen, and osbornite (a mineral otherwise found only in meteors) which suggests they originated in outer space.

Carbonados have been dated from 2.6 to 3.8 billion years old, which also might explain why they have only been found in Brazil and in the Central African Republic. During that span of the Earth’s history, what is now Brazil may have been joined to the western coast of Africa. (This “supercontinent” pairing actually preceded the better-known Gondwanaland). It is possible that a diamond meteorite struck the Earth at that time, accounting for carbonado’s current distribution."