Marble is a type of metamorphic rock mostly composed of calcite. In terms of hardness, marble is a relatively hard type of rock. On the Moh's hardness scale, which ranges from 1 to 10 where the hardest know material (diamond) is assigned the highest value, marble offers a 5. Marble is harder than many types of rock like sandstone but softer than others like granite (6.5 hardness). Since it takes considerable heat and pressure to form marble, fossils are rarely preserved within marble. Marble offers countless color and pattern variations.
Engraving marble with lasers allows for the creation of accurate, intricate designs that would be difficult to achieve by other means. Laser engraving is one of the most efficient ways to engrave marble. Computer-assisted laser engraving programs nearly take all the risk of making a mistake out of engraving marble. Even lifelike portraits can be engraved into marble with lasers. Headstones are often laser-engraved with pictures of the deceased.
Engraving hard stone like marble can be a difficult and time-consuming task if done with manual hand tools. Many manufacturers offer hand-held electric engravers that can be employed to engrave marble. Since marble is a hard stone however, the proper engraver attachment must be constructed out of a material harder than marble. Diamond-tipped engraver attachments can scratch any material including marble. Tungsten carbide is ranked a 9 on the hardness scale; a tungsten carbide attachment can easily engrave marble. Many rotary tools offer attachments that are designed to cut through or engrave marble.
Attempting to engrave marble can be a dangerous activity. Marble engravers should be familiar with the tools they are attempting to engrave marble with before attempting to engrave. Engraving marble can cause dust and debris from the work piece to become airborne. Respirators or dust masks should be in place before attempting to engrave marble to prevent dust and debris from damaging the lungs. Eye goggles prevent loose marble particles from damaging the eyes.