Silicon is rarely found in nature in its uncombined form. In fact it is amazing how rare native silicon is with 25.7% of the Earth's crust being silicon. Silicon, binds strongly with oxygen and is nearly always found as silicon dioxide, SiO2 (quartz), or as a silicate (SiO4-4). Silicon has been found as a native mineral only in volcanic exhalations and as tiny inclusions in gold.
Of growing interest in rock shops, however, are laboratory-grown silicon
boules. Most such specimens are end fragments or flawed discards from the
integrated circuit industry. Silicon boules are grown (pulled) from a molten
state from a seed crystal, in such a way as to produce a single large crystal
which must be completely without crystal defects, or the entire boule must
be discarded. Modern techniques can create a single crystal several feet
long and up to 10 inches in diameter. These large crystals are sliced into
very thin wafers, upon which complex integrated circuits can be etched.
The unused parts of the boule are often saved, and used as paperweights
or sometimes cut into
The word silicon (which is taken from the latin word for flint) can be confused with other terms. One of these terms was already mentioned: Silicate (SiO4-4). Silicates are minerals whose primary cation is the SiO4-4 ion group. Another confusing term is silica. Silica is a term used by geologists for SiO2 or silicon dioxide in any form whether it is in the form of quartz, or any of the Quartz Group members, or as a segment of the chemistry of a silicate, or even as silicon dioxide dissolved in water. A geologist might use the phrase, "The magma was rather poor in silica." Indicating an SiO2 content that was lower than expected. Yet another term is silicone. Silicone is a synthetic polymer that is made of silicon, carbon and oxygen and has many medical and some industrial purposes.