Minerals PDF

MINERALS Minerals Minerals are defined as naturally occurring, inorganic solids with definite chemical compositions and ordered internal structures. Each mineral is unique, but they display general characteristics. Minerals are formed naturally and exist without human intervent...

MINERALS Minerals Minerals are defined as naturally occurring, inorganic solids with definite chemical compositions and ordered internal structures. Each mineral is unique, but they display general characteristics. Minerals are formed naturally and exist without human intervention. Minerals are formed only through inorganic processes. Materials made from or made by organic materials and processes are not minerals. Inorganic liquids and gases are not considered as minerals. Minerals have exact chemical formulas containing elements and compounds in specific ratios. Some minerals exhibit atomic substitution as an exception to the abovementioned rule. Atoms in minerals have an organized, repetitive geometric pattern called a crystal structure. Volcanic glass, although formed naturally, is not a mineral due to being amorphous. MINERALOIDS Mineraloids Mineraloids are materials that fulfill all the requirements of being a mineral except having an organized internal structure. Some examples lack more than one requirement.  Amber Amber is fossilized tree resin. This formed millions of years ago from tree sap. May contain trapped organisms inside.  Opal Opal is a hydrated amorphous form of silica Although very similar to a mineral, its variable molecular structure disqualifies it from that category.  Pearl Pearls are hard, glistening objects formed by shelled mollusks. Mainly composed of CaCO3 May also be created artificially by implanting stimulus in shellfish COMPOSITION OF MINERALS Composition of Minerals Minerals are classified according to the elements that compose them. These elements are abundant in the Earth's crust. Composition of Minerals Minerals can be classified as: Silicates Oxides Sulfides Sulfates Halides Carbonates Native metals  Silicates Silicates are composed primarily of silicon-oxygen tetrahedrons. Examples include olivine and quartz.  Sulfates Sulfates consist of metal cations bonded to Sulfate anionic group. Usually precipitates out of water Examples include gypsum and copper sulfate.  Halides Halides consist of halogen ions bonded with other elements. Examples include rock salt and fluorite.  Carbonates Carbonates possess a carbonic ion. Examples include calcite and dolomite.  Native Metals Single or pure metals (elemental). Examples include copper and gold