The Beauty of Marble
Certain marbles have been valued since antiquity for sculpture and for architectural uses. The marbles prized for statuary are usually quite pure (i.e., white in color and free from inclusions or marks) and reflect light softly or semitranslucently due to their property of allowing some incident light to penetrate to a depth of about an inch (1–2.5 cm) before reflecting it.
Some marbles that show colorful patterning are used for decorative architecture. Patterning in marble arises from various trace minerals , most often silicates (e.g., quartz, olivine , garnet), graphite , pyrite, and organic substances. The magma responsible for metamorphosing the original limestone may also contribute impurities.
“Marble.” World of Earth Science. 2003. Encyclopedia.com. 21 Jul. 2013 <http://www.encyclopedia.com>.