Masons, or 'stonemasons' as they are sometimes called, work with marble, granite, limestone, and other materials to build walls, walkways, and arches, and to lay stone floors.

Using special tools such as hammers and chisels and water-cooled saws with diamond toothed blades, masons cut and shape their materials. They must also be able to use irregularly shaped rocks and turn them into a uniform structure - like a wall or floor. This takes skill and experience.

Informal, on-the-job training may be available to those serving as mason 'helpers,' but the best way to enter this profession is through a formal, three-year apprenticeship program, which includes both classroom and on-the-job training sponsored by local contractors or a union-management committee.

The work isn't easy. Like most of the building trades, masons must be able to do heavy lifting, and much of the work is outdoors in all kinds of weather. But it can be very satisfying. After all, a qualified mason is a master of stone - the oldest building material on earth.