Rustication is an architectural term referring
to a decorative treatment of the masonry of a structure's exterior. It is to
masonry what pastoralism is to literature, in that it pretends to be getting
back to very simple primitive roots while actually being the highly refined product of sophisticated
artists and artisans.
It was used as early as Roman times (particularly
in the reign of the Emperor Claudius), was particularly popular in the renaissance
and baroque periods, and is still in use today (see the interesting image
of rusticated cladding being applied to The Getty Center
in Los Angeles, California, below).
In its most extreme form, rusticated masonry is artfully carved so that the exposed
faces of the stone blocks look like boulders right out of nature. More commonly,
the stonework is ashlar (laid in repeating rows of rectangular headers and
stretchers), with the rusticated face often chamfered, or bordered by drafted
margins--that is, with bevels or smooth framing strips around the edges of the face, like
a picture frame. The joints are thus emphasized.
Rustication is often applied by picking (gouging) the surface (picked work), carving it into
meandering channels (vermiculate work), leaving pyramidal dimples on
the faces of blocks, and, most oddly, by carving the face of a block into the
appearance of stalactites or icicles (frost-work)! Sometimes the block faces are left smooth,
with the deeply chiselled chamfered joints doing all the work.
Rustication is usually confined to the ground floor of massive buildings (but
see the Palazzo Strozzi URL, below), to add to the anchoring
feel of that portion in contact with the earth. Sometimes it forms a surround
around entries. The masonry is generally fabricated from large stone blocks,
and the effect is of massive primitive strength (by emphasizing the sheer bulk
of the big blocks).
Below you will find a URL for an image of the astounding vermiculate-rusticated
ground-floor of the 1725 Chiswick House, London--see the
strongly drafted margins. In addition, it's worth noting the Victorian Richardsonian
Romanesque (widespread, USA) which featured intense rustication to
emphasize the style's putative getting back to the medieval after the clean
lines of colonial, Greek revival, and other earlier 19th-century styles.
If you look long enough you will find brick being made to imitate rusticated
stone, and even stucco performing this task. Rustication is not restricted to
facades; it often appears in bands on columns (the effect is strange, to say the
least: see the Pevsner site, below).
At times in the distant past, real boulders were more or less dressed so as to be
fit into a wall; this is called "cyclopean" work in its rougher form, and "polygonal"
masonry in a slightly more refined form. The Greeks and Romans both used these styles, as did the Incas.
This stuff is the real thing.
http://www.ontarioarchitecture.com/rustication.htm (A site describing rustication,
http://www.nycjpg.com/prenycjpg/Archives/20020629.htm (Rusticated masonry in
the American Museum of Natural History.)
gateway by the great English architect Inigo Jones.)
rustication, Palazzo Medici-Riccadri, Florence.)
rustication, Palazzo Strozzi, Florence.)
from the Pevsner Architectural Guide.)
http://academic.reed.edu/getty/cafeteria/Caf-Res-21.jpg (Rusticated travertine
cladding being applied at the Getty Center.)
(Macchu Picchu polygonal masonry.)