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Chemical Characteristics of Ohio Minerals

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Elements in Ohio Minerals

The chemical components of minerals are elements and elemental groups. An "element" is a distinct variety of matter, which by itself or in combination with other elements, make up substances of many kinds. For example, gold is an element. It also is substance that is familiar to many people. The substance called gold is made up almost entirely of the element that also is called gold. Therefore, when we speak of the mineral gold, we call it "elemental gold." This means that it consists of just one element, gold, rather than a combination of elements. On the other hand, the mineral pyrite consists of two elements: iron and sulfur. When we speak of this mineral we call it just "pyrite." The major chemical elements that are found in Ohio�s minerals are as follows:


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Element Symbol
aluminum Al
magnesium Mg
barium Ba
manganese Mn
calcium
Ca
nickel Ni
carbon C
oxygen O
chlorine Cl
phosphorus P
chromium Cr
potassium K
copper Cu
silicon Si
fluorine F
sodium Na
gold Au
strontium Sr
hydrogen H
sulfur S
iron Fe
titanium Ti
lead Pb
zinc An

Elemental Groups in Ohio MineralsAn "elemental group," however, consists of more than one element. Elemental groups do not exist by themselves. Rather, in combination with other elements they make up substances such as minerals. Sulfur and oxygen together in the proper combination make up what is known as the "sulfate" elemental group. This group, in combination with the element barium, form the mineral barite. The major elemental groups that are found in Ohio�s minerals are as follows:

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Elemental Group Symbol Elements
carbonate CO3 carbon and oxygen
oxalate C2O4 carbon and oxygen
phosphate PO4 phosphorus and oxygen
silicate (hemimorphite type) Si2O7 silicon and oxygen
silicate (mica & clay type) Si4O10 silicon and oxygen
silicon dioxide
SiO2 silicon and oxygen
sulfite
SO4 sulfur and oxygen
water H2O hydrogen and oxygen

Mineral Classes

Most of the minerals in our world have precise chemical structures. For example, the mineral pyrite consists of one part of iron with two parts of sulfur. We write the formula for this mineral as "FeS2" using "Fe" to indicate iron and "S" to indicate sulfur. The mineral galena has sulfur in its structure also, but it has the metal lead instead of iron. We write its formulas as "PbS" to indicate one part of lead (Pb) with one part of sulfur (S). And so it goes, with each mineral having a chemical formula which reflects its chemical constituents. Because of this consistency in chemical structure it is possible to classify or group minerals. Mineralogists have done just that in order to make it easier to study and understand the wide diversity of minerals, and to understand the relationships between minerals. Following are the chemical classes of Ohio�s minerals:

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Chemical Class Character Examples
native elements single elements, uncombined sulfur (S)
sulfides elemental sulfur (S) combined with different metals pyrite (FeS2)
oxides elemental oxygen (O) combined with different metals hematite (Fe2O3)
halides elemental fluorine (F) or chlorine (Cl) combined with different metals fluorite (CaF2)halite (NaCl)

See Also