Optical Dish Carving

Smokitrine

The stone I’ve used to illustrate my technique is a “smokitrine,” a smoky brown quartz with yellow streaks. (While ametrine is a combination of amethyst and citrine, this quartz variety combines smoky quartz and citrine).

Tools For Optical Dish Carving

Below is a photo of the tools I use for carving. They include two diamond ball burrs to start the dimple and a set of wood dowels on 1/8” rods. (I use wood because I feel it’s more forgiving than steel or brass). I bought the diamond bits but made the wood tools. If you want to make your own, start by drilling a hole in a dowel, then epoxy it to a brass rod. When dry, put the unit in a flex shaft. File and sand it to shape as it turns. Use a radius gauge to ensure all the curved surfaces have the same shape. You’ll need at least three or four of each size, one for each grit you’ll use, and one for the polish.

Optical Dish Carving Techniques

Shape the gem before adding the optical dishes. In this case, I faceted the gem. Don’t polish the flats until you’ve finished the optical dishes. This gives…