Flat band with 5mm bezel set stone in sterling silver or 9ct yellow, white or rose gold
6mm wide by 2.5mm thick.
Inlaid horsehair flat braid or short hair/fur/ashes set in crystal resin 3mm channel
Many stones are available, you can choose from topaz, amethyst, red garnet, peridot or cubic zirconia for the same price - see the Gemstones collection for photos. Or contact me for other options.

Last pic is an example of a bezel setting from the side so you can see the height above the ring.
Hallmarked
Rings are made to measure, I send a ring sizer out when an order is placed.