Heliodor - optical dish carvingHeliodor - optical dish carving

Optical Dish Carving

Optical dishes are concave facets used in fantasy-cut gems. Learn this optical dish carving technique for creating your own unique gemstone designs.

2 Minute Read


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.

Tools for optical dish carving

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…

Howard Broderson

I got my start in gem cutting in 1957 and have progressed over the years into most forms of jewelry creations. I cut cabs, facet most kinds of gem materials (no diamonds). I carve wax patterns, make rubber molds from my patterns, inject wax patterns and then cast in sterlium plus, sterling silver and/or gold. In 2000 & 2001 I took 1st place at the International Gem Society in jewelry Design. In 2001 I took 1st place at the International Gem Society in Gem Carving. I also use a computer design program for cutting my faceted gems that has over 5,000 facet designs, plus I can also design my own. Using the right angles on faceted gems will produce better light return and make a much prettier stone. See Howard's work here.

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