Minerals - Part IIMinerals - Part II
7 Major mineral groups7 Major mineral groups
Nature’s most common building block in Nature’s most common building block in rock forming minerals is the …rock forming minerals is the …
Silica Tetrahedra SiOSilica Tetrahedra SiO44
1) Silicate Minerals1) Silicate Minerals
Quartz is the Quartz is the secondsecond most abundantmost abundant mineral on the mineral on the earth’s crustearth’s crust
(the most abundant element on the (the most abundant element on the earth’s crust is therefore earth’s crust is therefore oxygenoxygen))
Quartz is used for Quartz is used for glass, jewelry and glass, jewelry and electronicselectronics
FeldsparsFeldspars
Feldspar is the Feldspar is the
most abundant most abundant
““family” of minerals family” of minerals
on the earth’s crust. on the earth’s crust.
The various feldspar The various feldspar
minerals make up minerals make up
over over 60 percent60 percent of the crust. of the crust. ((AluminumAluminum ions replace silicon ions) ions replace silicon ions)
FeldsparsFeldspars
Feldspar is used for Feldspar is used for ceramics (china) and ceramics (china) and glassglass
MicasMicas Micas are soft Micas are soft
silicates found in silicates found in many rocks - many rocks - micas most micas most distinctive feature distinctive feature is that it has is that it has oneone cleavage surface – cleavage surface – they are pearly and they are pearly and ‘flake’ easily ‘flake’ easily
Micas Micas
Micas are used for Micas are used for
electronic electronic insulationinsulation
AmphibolesAmphiboles
– – complex complex type in the type in the silica group silica group where iron where iron and and magnesiumagnesium have m have replaced a replaced a silicasilica ion. ion.
CarbonatesCarbonatesCarbonate mineral group is made up of Carbonate mineral group is made up of compoundscompounds of of one carbon one carbon andand 3 oxygen 3 oxygen atoms (COatoms (CO33) joined with various metal ions) joined with various metal ions
CarbonatesCarbonates
reactreact with acid (HCl); with acid (HCl); calcite reacts calcite reacts strongly with acid, strongly with acid, other carbonate other carbonate minerals react only minerals react only mildly with acid.mildly with acid.
Other Carbonate MineralsOther Carbonate Minerals
Dolomite = Dolomite = CaMg(COCaMg(CO33))22
Siderite = FeCOSiderite = FeCO33
OxidesOxidesMetalMetal + oxygen = oxide + oxygen = oxide For example: For example: Hematite = FeHematite = Fe22OO33
Franklinite = Franklinite = (Zn,Mn,Fe)(Zn,Mn,Fe)22+ (Fe,Mn)+ (Fe,Mn)33+2O+2O44
SulfidesSulfides
MetalMetal + sulfur = + sulfur = sulfidesulfide
For Example: For Example: Pyrite = FeSPyrite = FeS22
SulfatesSulfates
SulfurSulfur + 4 Oxygen + 4 Oxygen atoms = Sulfate atoms = Sulfate SOSO44
For example: For example: Barite = BaSOBarite = BaSO44
Halites (Salts)Halites (Salts)
Compounds of elements and chlorine, Compounds of elements and chlorine, fluorine, iodine or brominefluorine, iodine or bromine
For example: For example:
table salttable salt = NaCl, = NaCl,
potassium salt = KClpotassium salt = KCl
Native ElementsNative Elements Elements found Elements found uncombineduncombined with other with other
elements, For example:elements, For example:goldgold
silversilver
coppercopper
sulfursulfur
diamonddiamond
7 Mineral Groups 7 Mineral Groups (in relative order of abundance)(in relative order of abundance)
1.1. SilicatesSilicates – minerals that contain silicon & – minerals that contain silicon & oxygen, and usually one more elementoxygen, and usually one more element
2.2. CarbonatesCarbonates – contains carbon w/3 oxygen – contains carbon w/3 oxygen atomsatoms
3.3. SulfatesSulfates – contains sulfur w/four oxygen – contains sulfur w/four oxygen atomsatoms
4.4. HalidesHalides – compounds of certain elements and – compounds of certain elements and chlorine, fluorine, iodine or brominechlorine, fluorine, iodine or bromine
5.5. OxidesOxides – compounds of elements and oxygen – compounds of elements and oxygen (usually rust looking)(usually rust looking)
6.6. SulfidesSulfides – compounds of elements and sulfur – compounds of elements and sulfur7.7. Native ElementsNative Elements – elements found – elements found
uncombined w/other elements (copper, gold, uncombined w/other elements (copper, gold, etc…)etc…)
Single chain silicates… Single chain silicates…
End hereEnd here
Look familiar?Look familiar?
Felspar…Felspar…
MicroclineMicrocline
Distinguishing Distinguishing feature:feature:
the the ‘laminae’ – ‘laminae’ – little veins in little veins in the mineralthe mineral
GarnetGarnet
CaCa33AlAl22(SiO(SiO44))33
Look familiar?Look familiar? Hornblende:Hornblende:
striated striated appearance appearance
hexagonal cross-hexagonal cross-section section
Dark-dark green Dark-dark green to blackto black
Look familiar?Look familiar?
MagnetiteMagnetite magneticmagnetic
Look familiar?Look familiar?
OlivineOlivine Light to dark greenLight to dark green Really hard (6.5-7)Really hard (6.5-7)
Look familiar?Look familiar?
FrankliniteFranklinite Stubby metallic Stubby metallic
crystals, usually crystals, usually in calcitein calcite
Look familiar?Look familiar?
ZinciteZincite redred vitreousvitreous orange-yellow orange-yellow
streakstreak
WillmeniteWillmenite greengreen strongly fluorescent strongly fluorescent
green green