SILICON POLYCRYSTALLINE E14
A specimen of pure Silicon Polycrystalline E14. Silicon is Element 14 on the Periodic Table. Very shiny and silver in colour. A relatively light metal to add to your collection.
5.8cm x 5.6cm x 3.4cm, 81g.
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. It binds strongly with oxygen and is nearly always found as silicon dioxide, SiO2 quartz, or as a silicate (SiO4-4).
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 as a molten state from a seed crystal. The crystal must be without defects, or the entire boule is 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 or printed.
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 Group members, chemistry of a silicate, or 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.
colour is iron-black, dark silver-gray to bluish brown.
Luster is metallic.
Transparency: Crystals are opaque.
Crystal System is isometric; 4/m bar 3 2/m
Crystal Habits are microscopic crystals and inclusions.
Cleavage is absent.
Fracture is conchoidal.
Hardness is 7.
Specific Gravity is approximately 2.3.
Streak is black
Associated Minerals are limited to gold where silicon is found as inclusions. Silicon has been found as a native mineral in volcanic exhalations.
Notable Natural Occurrences include Nuevo Potosi, Cuba; Tolbachik, Kamchatka and Kola Peninsula, Russia.
Best Field Indicator: Found with computer circuits etched on the surface!