Answer: You can read about asterism, or the “star effect,” and the inclusions that cause this optical phenomenon in gems in the International Gem Society article (IGS) on phenomenal gems. For cutting star gemstones, some introductory books and articles may help.
Reading Material for Cutting Star Gemstones
I’ve cut several star gemstones. There are three books I’d recommend that will tell you how to cut and polish star stones and what equipment you’ll need: Advanced Cabochon Cutting by Jack R. Cox, Star Gems by Douglas L. Hoffman, and Gem Cutting by John Sinkankas. Any of these will help you understand how to work with star gemstones.
For basic information on cabochon cutting, you can review this IGS article on the fundamentals of lapidary. For more detailed advice, you can also review this IGS article on cutting star and cat’s eye gems.
When you’re ready to purchase stones and equipment, check out the IGS recommended suppliers list.
I hope this helps.