The Following is an excerpt from the Book "Patio and Stone" by Tom Wilhite on Types of Boulders on page 21.
This is a simple yet very informative excerpt on boulders and the types.
" BouldersA boulder by definition is a detached and rounded or much Warren Mass of rock. It may be huge or relatively small, rough-edged or smooth, but it is truly the most raw of materials, highly evocative of the natural landscape.
Fieldstone perhaps the most familiar type of Boulder, is any stone found lying in a field or buried beneath the soil. Beal Stones offered for sale in stone yards may also have been salvaged from an old wall or building that has been torn down. These rocks have been aged by being exposed to the elements and are often decorated with lichens or Moss. Some are attractive enough to hold their own as garden sculptures( due to their varied colors and interesting shapes) and all are excellent for creating a primitive or antique look in the garden. Some are flat enough to use as rough stepping stones for flooring for a rustic patio. If the shape is right, they can make interesting steps when set into a hillside.
Quarried Boulders have been with blasted or Doug from larger formations, so they often have angular, Jagged surfaces that can be quite dramatic as focal points in a landscape. They may also have attractive veining contrasting color. Basalt columns are tall, relatively narrow pieces of stone that can serve as garden accents for as fountains when a hole is drilled through them from top to bottom.
River washed boulders have been smooth and shaped by flowing water. These Stones often have a more uniform texture than feel stones, and their overall shape can be exquisitely graceful. They're rounded Contours can be reminiscent of a Henry Moore sculpture, but, of course, at considerably lower cost. They are also a natural choice for water features.
Wall Stone, as its name indicates, is used to build dry stack or mortared walls, built it can also be used for edging. Wall stone comes in two general categories: rubble, which is uncut or roughly squared, and ashlar, which is neatly trimmed into a block shape and can be laid almost as easily as brick. "
Brick House Stone Masonry 309 Clarence St. London, Ontario N6B 2K2 (226) 781 - 1046