MineralsMineralGroups

2.2WhatareMinerals?5 characteristics of ALL MINERALS: 1.  Naturally occurring (formed naturally) 2.  Solid substance 3.  Orderly crystalline structure (atoms and ions are

arranged in a repeating pattern) 4.  Definite chemical composition (most are made up

of two or more elements) 5.  Generally considered inorganic (non-living)

2.2HowdoMineralsForm?•  FormnearlyeverywhereonEarth,underdifferent

condi:ons.ex.deepincrustormantleofEarthwithhightempsandpressure–silicates.

•  Thereare4majorprocessesthroughwhichmineralsform:

1.  Crystalliza:onfrommagma2.  Precipita:on3.  Pressureandtemperature4.  Hydrothermalsolu:ons

2.2HowdoMineralsForm?1.Crystalliza:onfromMagma•  Magma=moltenrock(formeddeepwithinEarth)•  Whenmagmacools,elementscombineandminerals

form•  Firstmineralsthatcrystallizeandusuallythosethat

havealotofiron,calciumandmagnesium.•  Composi:onofmagmachangesasmineralsform:

sodium,potassiumandaluminumarethenmostcommoninminerals.

MineralsFormedasaResultofCrystalliza:onofMagma

2.2HowdoMineralsForm?2.Precipita:on•  Waterinlakes,rivers,ponds,oceans,aswellaswater

underground,allcontainsdissolvedsubstances.•  Whenwaterevaporates,someofthesesubstances

willreacttoformminerals.•  Changesinwatertemperaturecanalsocause

dissolvedmaterialstoprecipitate.•  Limestoneandcalciteareexamples.

2.2HowdoMineralsForm?3.PressureandTemperature•  Whenexis:ngmineralsundergochangesinpressure

andtemperature,mineralscanform.•  Highpressurecanmakeamineralrecrystallizetoforma

morecompactmineral.•  Temperaturechangescanmakemineralsunstableand

newmineralswillform.•  Talcandmuscoviteareexamples.

2.2HowdoMineralsForm?4.HydrothermalSolu:ons•  Hydrothermalsolu:on:veryhotmixtureofwaterand

dissolvedsubstances.•  Tempsbetween100-300degreesCelcius•  Whenincontactwithexis:ngminerals,thesesolu:onsgo

throughchemicalreac:onstomakenewminerals.•  Sulfurmineralsareexamples.

2.2MineralGroups

Mineralscanbeclassifiedintogroupsbasedontheircomposi:on.1.  Silicates2.  Carbonates3.  Oxides4.  Sulfates&Sulfides5.  Halides6.  Na:veElements

1.Silicates

• Silicon and oxygen combine to form a structure called the silicon-oxygen tetrahedron. This silicon-oxygen tetrahedron provides the framework of every silicate mineral.

2.Carbonates• Minerals that contain the elements carbon, oxygen,

and one or more other metallic elements

3.Oxides• Minerals that contain oxygen and one or more other

elements, which are usually metals

4.SulfatesandSulfides

• Minerals that contain the element sulfur

5.Halides• Minerals that contain a halogen ion plus

one or more other elements

6.Na:veElements

• Minerals that exist in relatively pure form