People have used stone engravings throughout the centuries for various purposes, from chronicling important historical events to memorialising loved ones. Granite poses a special challenge to the amateur stone engraver due to its extremely hard surface, which also makes it an especially popular stone choice for headstones and rock memorials because of its long lifespan. Most monument companies opt for sandblasters when working with granite, but even entry-level micro-sandblasters can cost £1,300 to £1,950, so unless you're planning on engraving a lot of granite, your best tool option is an electric engraver which uses a special set of diamond tips to carve into the rock.
Develop a general design plan for your granite engraving. Think about the specifics of your granite project, including the size and shape of the design you'd like to engrave, in order to determine the general stone size that you'll need. Draw a sketch of your design on a piece of graph paper.
Find granite that is suitable for your engraving project.
Wash your granite with soap and hot water. Place the stone on a towel to air-dry. Cover a sturdy table with old newspaper and transfer your design to the surface of your dried granite stone using a wax pencil.
Put on safety goggles to protect your eyes from the dust that will come from your granite during the engraving process. Position a diamond tip into the end of your electric engraver and begin engraving your design into the granite, starting with the main outlines of the design. Press lightly and move the engraver slowly to allow the tip enough time to chisel the hard granite.
Clean the rock dust off the surface of the granite with a towel as you work. Switch tips, depending upon the type of design that you're creating; according to Inland Craft, a ball tip works well to engrave the outline of your design but you should switch to the cone and cylinder tips if you want to do more detailed work such as circles, dots and writing. Turn your engraver off and allow the motor to cool down every 15 to 20 minutes to minimise stress to your motor from the hard granite.
Inspect your granite stone to ensure that you engraved all the markings completely. Engrave any sections you missed. Wash the rock off with hot water and allow it to air-dry.
If you live in an area that has native granite, you may be able to save money by harvesting your own granite from your land. According to Jack C. Rich, author of "The Materials and Methods of Sculpture," states that produce granite include Vermont, Maine, Massachusetts, Pennsylvania, Minnesota, North Carolina and Texas. You should also be able to find a wide selection of granite stones available for purchase at your local rock yard.
Always wear goggles during the engraving process to protect your eyes from damage or irritation from the rock dust.