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Basic

The basic silicon tetrahedron, SiO4, has one silicon atom in the middle with four oxygen atoms surrounding it. If you draw straight lines from each of the oxygen atoms, the shape of a tetrahedron appears as triangles on each side. One oxygen atom sits on top of the tetrahedron where all the points meet while the otherthree form the corners of the triangles.

Chains

The pyroxene group of minerals contains the silicon tetrahedron in chains. An example of a pyroxene is diopside, or CaMgSi2O6. Each tetrahedron in the single chain is connected to the next one at a corner, with each tetrahedron sharing twoof the oxygen atoms from the adjoining structure. This creates a long single chain.Double Chains

Double chains, such as amphiboles, use the same structure as single chains withthe exception that a third oxygen atom is shared. Hornblende is the most abundant form of amphibole -- a black mineral found in igneous rocks.

Sheets

Each tetrahedron shares three of its oxygen atoms with another tetrahedron in the sheet arrangement. The unshared atom points in the same direction in each tetrahedron on a sheet. Silicon tetrahedrons stack on top of each other, like sheetsof a substance.

Framework

The framework arrangement takes the basic arrangement and then connects each tetrahedron to another at the corner in a continuous 3D structure. Examples of thisarrangement are quartz and feldspar.

Minerals

Minerals are natural substances created through geological processes. Accordingto the International Mineralogical Association, a mineral must be a naturally occurring element or chemical compound that is normally crystalline in structure and formed through geological processes. New classifications include both inorganic and organic minerals. Minerals are found in all parts of our life, from our t

oothpastes to meteorites that traveled light years through space.Silicate Class

The silicate class is one of the most complex classes of minerals. Based on their structure, the silicates are divided into six subclasses: neosilicates, sorosilicates, inosilicates, cyclosilicates, phyllosilicates and tectosilicates. The neosilicate class is made up of silicates where the SiO4 tetrahedron, the basic chemcial unit of all silicates, is unbonded to other tetrahedrons. The neosilicates include aluminum silicate, magnesium silicate and iron silicate. Sorosilicates have two silicate tetrahedrons bonded by an oxygen molecule. It is the smallest of the silicate subclasses and includes beryllium silicate hydroxide, calciumboro-silicate and calcium aluminum silicate hydroxide. Inosilicates can be a single- or double-chained silicate. In the single-chained inosilicates, the tetrahe

drons are bound by two oxygen molecules. In double-chained inosilicates, two single chains are side by side. This subclass includes sodium iron silicate and sodium iron silicate hydroxide. Cyclosilicates, such as beryllium aluminum silicate

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and copper silicate hydroxide, are chained like the inosilicates, but the chains themselves form a ring structure. Phyllosilicates are silicates where the rings of tetrahedrons are bound to other rings with an oxygen molecule, examples ofwhich include magnesium silicate hydroxide and iron magnesium silicate hydroxide. Tectosilicates, also known as framework silicates, are silicates where the four oxygen molecules of each SiO4 tetrahedron is shared with another tetrahedron.The tectosilicate subclass is further broken down into five groups: the feldspar

, quartz, feldspathoid, scapolite and zeolite groups.Carbonate Class

Carbonates are a less complex class than the silicates and have some common characteristics found in most carbonates. These characteristics include being somewhat soluble in acid, average to above average density and good cleavage. The carbonates include two smaller subsets in addition to regular carbonates; these subsets are the rare earth carbonates and uranyls. Uranyl carbonates contain uraniumand rare earth carbonates are also commonly known as rare earth minerals or ele

ments.Common Uses

Silicates are common as semi-precious stones known as quartz, agate and garnets.They are also used in microchips, glass and ceramics making. Magnesium silicateis also known as talc or talcum powder and is commonly used in cosmetics and ba

by powder. Carbonates including calcium carbonate are used in agriculture, medical fields and even chalk.