Getting Started

A Brief Discussion of Gem Stone Cutting Equipment

There are two different areas of gems stones - one is cabochons - which are usually made of opaque stones and have a flat back. Then there are the faceted stones (what most people think of as gems) these are like diamonds and rubies etc. The equipment and methods etc. are totally different for the two.

Cutting cabochons is usually where most people start - mainly because it is easier, less expensive for materials and equipment, and tends to be something you can learn fairly quickly.

Cutting faceted stones is a bit trickier - you can do it by hand if you are very patient (I mean you have to spend days at it!) and the equipment and methods are very precise and expensive.

Two publications I would recommend to you are Lapidary Journal and Rock and Gem - they have articles on everything you need to know and extensive listings of shops and supplies as well as putting out videos and books. You should be able to get these at a major bookstore or from a subscription. Read before you buy! Books are cheaper than broken or the wrong equipment.

Here is a run down on the equipment for cutting cabochons:

-an arbor - basically a shaft with a place to mount stones on and a sander/polisher comes in two common sizes - 6" and 8"

-100 grit Silicon Carbide stone - removes material quickly - you can buy Diamond wheels but this will do the trick till you know you need to buy better

-a Scott-Murray expanding drum - uses pre-made belts - the type that clamp the paper in always bump too much for my liking

- 220, 360, 400, and 600 grit belts - you can get lower (coarser) and Higher (finer) but these will do the trick.

-A flat buff plate - fits on the end of the arbour shaft like a disc sander – in fact you can get sand paper to fit them - you will need a felt buff for this and a leather buff - also polishing compound - either tin oxide or cerium oxide (I like cerium - mainly because I do a lot of agate)- also you can add a bit of Linde-A to the polish - makes the shine come up faster.

-dop sticks - basically short chunks of ¼" dowel to twirl the stone with

-dop wax - a low temp wax that sticks well to stones and cools to a hard texture

-dop wax melter - I use an electric coffee pot warmer - and a can - cheap and works better than the commercial ones - in a pinch a hot plate can be used but make sure your fire insurance is paid up.

About $500 will get you a really nice setup (some used equipment or homemade)

Here is a blurb on cutting Cabochons - incomplete but a start

Your First Cabochon

First a bit of history etc. The word cabochon comes from the old French word Cabo -which means head. This refers to the round shape of the stone when completed. Originally all gems were cabochons as faceting was not possible till more advanced methods appeared.

The most basic cabochon is a calibrated cabochon. That is a stone that is ground to a dimensional shape i.e. an oval or circle of a set size. This allows for a pre-made mount to be used to set the stone. These mounts are readily available and if you don't make your own jewelry are a handy way to display your creation.

There are several different forms of a calibrated cabochon. There are low, medium and high dome cabs (short form for cabochon). Also there are several ways to finish the backs of the cab - from plain to

turning the stone into a double cab. Try a medium sized cab first (small ones are hard on finger tips - big ones take too long) in a material of 5 - 6 on the Moh's scale. Once you have the basic technique down you can move to more challenging materials.

Okay now for the Fancy stuff - faceted stones:

For this you will need:

A faceting machine or a hand faceter and plates

diamond wheels or compounds - they go from coarse to remove material quickly up to a very fine polish

transfer block

special dops

indexing head

plans for the stone (details on angles etc.)

a lapidary grinder for pre-forming the stone

About $2500 for the mechanized approach (not cheap!) and it is something you need to be taught to get going with out a lot of grief.