From the International Gem Society Reference Library

 

Introduction
... Lapidary is a hobby that is enjoyed by people of all ages and circumstances. Unlike most hobbies, what you produce is actually worth more than the labour you put into it. For many cutters, their hobby becomes a part time, or full time profession. 
... Gem cutting can be done with a minimum of equipment, or an elaborate set up with enough bells and whistles to impress your most fastidious neighbours. The fundamentals, enough to do good quality work, are easy to learn. On the other hand, you will never learn everything, or run out of new challenges.

Tumbling
... There are many styles of lapidary. Tumbling is the simplest and least expensive method. This is where the rough material is put in a revolving barrel with abrasives. Progressively finer abrasives are used until a polish is obtained. This process closely resembles what happens to rocks in a stream or on the beach, except that the level of polish is much higher. It is often a family activity, working with stones collected on vacation.

Cabbing
... Cutting cabochons is probably the most common form of gem cutting. Cabs are gems with a flat bottom and a curved or domed top. If you can envision an opal or a piece of tiger's eye, you are looking at a cab.
... Cabs have distinct resale value, based on the material they are cut from, and their cutting can be profitable. This makes for an excellent, indoor hobby. It is especially enjoyable if you are cutting materials you have found yourself.
... Cabochon cutting is a step up in complexity from tumbling and it requires a greater investment in tools. If you have the skills you can make your own equipment, which keeps the cost down. If you are buying new tools, the prices range from a couple hundred dollars to over $1,000 for top quality.
... It only takes a little practice to become proficient and is something almost everyone can learn to do well. A word of warning though, cabbing can be highly addictive! (Photo - Cabs and jewellery by Sigrid Heiss and Malcolm Jackson)

Faceting
... Faceting is the style of cutting that has the greatest profit potential. Many faceters are semi-professionals. They sell enough gems to support their hobby, or to bring in some supplemental income for their family. For those interested in collecting or investing in gems, this is by far the most practical way to go. The price of rough and labour is almost always less than the wholesale price of the finished gem.
...If you want to facet gems, for fun or profit, expect to invest about $2,000 in tools to get started. If you have a machine shop, you can make your own. Here, more than in the other styles, the quality of your equipment will greatly affect both the quality of your work and the enjoyment you get out of it.
... Faceting is one of those art forms that you can become good at with a minimum of experience, but also one where you will never run out of new challenges. Nor does it require any esoteric "artistic" sense. Machinists, engineers, and people good at maths often excel in faceting.

Carving
...Carving is the most challenging of the lapidary arts and there are very few recognized experts in the field. You cannot simply go out, buy a set of carving tools, and begin cutting. Often you are required to make your own tools, or improvise.
... Besides the lack of manufactured tools, one must have a distinctive artistic sense and a thorough understanding of the principles of lapidary. More than when working in wood or metal, the materials present definite limits as to what can be done.

Other Styles
... Tumbling, cabbing, faceting, and carving represent the most common forms of lapidary work, but this by no means exhausts the list of things you can do with stone. Some folks create useful items like door handles, drawer pulls, boxes, and handles for knives and table wear. 
... Intarsia is a method of gluing colourful pieces of gem material together, then finishing them like a cabochon. Stones are inlaid in wood boxes and guitar necks. You can use your cabs as a "canvas" and finish them by painting. 
... The useful things you can create from stone are only limited by the imagination of the artist.

Getting Started
... Before beginning in lapidary, you should understand what tools are required for each of the different disciplines. This series will go into tumbling, cabbing, faceting, and carving in detail. Some tools can be used for different styles, while others are specific to one type of cutting alone. By knowing what you would like to do, you can avoid buying unnecessary equipment. 
... What kind of work to do is primarily a matter of personality, although budget can certainly place limits on your enthusiasm. Choose a style that suits your personality. Consider the following aspects: Do you prefer artistic work or mechanical cutting? How much time can you spend at it? Do you expect to be working alone, or will you be involving your spouse or children?
... You also need a source for materials. Will you be gathering your own rocks? If so, the kind of stones you are able to find will make a difference in the kind of lapidary work you can do. Are you willing to purchase some or all of your rough?
... One of the best ways to get started is to find a local gem and mineral club. (**There’s one in Goede Hoop St, Bothasig!).  They have classes on lapidary and tools you can practice on. Just ask them any questions you may have!

To read further articles on this topic, go to:
Part 2, Making Smaller Pieces
Part 3, Tumbling
Part 4, Cabochon Cutting
Part 5, Faceting

http://www.gemsociety.org