181
edits
Changes
Jump to navigation
Jump to search
Line 1:
Line 1: − The '''silicates''' are the largest and the most complicated class of minerals. Approximately 30% of all minerals are silicates and geologists estimate that 90% of the crust of the Earth is made up of silicates. This is so since [[oxygen]] and [[silicon]] are the two most abundant elements in the Earth's crust.+ − The basic chemical unit of silicates is the (SiO<sub>4</sub>) tetrahedron shaped anionic group with a negative four charge (-4). The central silicon ion has a charge of positive four while each oxygen has a charge of negative two (-2) and thus each silicon-oxygen bond is equal to one half (1/2) the total bond energy of oxygen. This condition leaves the oxygens with the option of bonding to another silicon ion and therefore linking one (SiO<sub>4</sub>) tetrahedron to another and another, etcetera.<ref>[http://www.galleries.com/minerals/silicate/class.htm]</ref>+ − The complicated structures that these silicate tetrahedrons form is truly amazing. They can form as single units, double units, chains, sheets, rings and framework structures. The different ways that the silicate tetrahedrons combine is what makes the Silicate Class the largest, most complicated class of minerals. − − The Silicates are divided into the following subclasses, not by their chemistries, but by their structures: − − *Nesosilicates (single tetrahedrons) − *Sorosilicates (double tetrahedrons) − *Inosilicates (single and double chains) − *Cyclosilicates (rings) − *Phyllosilicates (sheets) − *Tectosilicates (frameworks) − − − ==Reference== − <references/>
Rewrite copy and paste material
A '''silicate''' is a mineral made up of of [[silicon]] and [[oxygen]]. These two elements form a significant amount of the Earth's crust and likewise silicates are a significant portion.
Silicates are often of the form SiO<sub>4</sub> which forms a [[tetrahedron]]. These units can then be linked together to form regular [[latice]]s - either chains, sheets, or larger frameworks.
[[Category:geology]]
[[Category:geology]]
[[category:Minerals]]
[[category:Minerals]]