I make these rings from round solid copper and sterling silver wire. Once I've made the ring I take it through a rolling mill a couple of times to make it flatter, then I take only the tip through the rolling mill several times to give it the teardrop shape. This process gives it an organic, one of a kind look, almost a perfect teardrop shape.
I then saw the ring open and polish the ends so they will go through your piercing smoothly. To finish I mattify it and oxidize it, then i brush some of the oxide off, each ring has a slightly different finish.
They are made with 18g (1mm), 16g (1.2mm) and 14g (1.6mm) with inside diameter 10mm or 8mm and 12g (2mm) in 10mm inside diameter making them suitable for most septum piercing.
The first six pictures shows rings in 14 and the two, the 7th picture is of 16g 10mm and the 8th picture of 16g 8mm.