By Pariah offers an intriguing range of jewelry and they use lab diamonds to great (and cost effective) effect.

Here, though, they use what they are calling a stone trilogy, with moss agate, green chalcedony and recycled sterling silver bands. A great look if you tend to stack rings. My only caution would be that rings made of materials like this can be fragile if you talk with your hands (as I’ve found to my great regret!)

This sells for USD$697.