EARTH
MATERIALS
Mineral: definition
- Solid
- Crystalline
- Inorganic
- Naturally occurring material
- Fixed range of chemical composition (
e.g plagioclase : feldspar)
- Fixed chemical composition
- Ordered atomic arrangement
Classification Based on
:
Structural aspect
Compositional aspect (anion complex :e.g
–(PO4,-CO3, OH)
Standardization (nomenclature) :
Class-----subclass
(silicates,
oxides,hydroxides,carbonates,phosphate, sulphate,sulphides,halides, native
elements)
Group
----subgroup
[ amphiboles(hornblende), plagioclase(albite,
anorthite,orthoclase,microcline :feldspar) ]
Subclasses
: silicates
Nesosilicates
(GAKOSTS)
Garnet,
andalusite,kyanite,olivine,staurolite,topas,silimanite
Sorosilicates,
Epidote,lawsonite
Inosilicates,
Single chain :
pyroxene(augite) and diopside
Double chains:
hornblende
Cyclosilicates,
Beryl, tourmaline
Phylosilicates,
(BSMC)
Talc,biotite,serpentin,muscovite,chlorite
Tectosilicates
(QPM)
Quarts,plagioclase,
microcline
Other
classes :
Oxides : hematite,magnetite,ilmenite,corundum,cassiterite
Hydroxide :
bauxite,goethite
Carbonates : (cams)
calcite,aragonite,malachite,siderite
Phosphate : apatite
Sulphate :
barite,gypsum
Sulphide(bling2) :
galena,pyrtite,sphalerite
Halides :
halit,fluorite
Native elements :
sulphur, graphite
PHYSICAL CHARACTERISTIC
OF MINERALS :
- . Colour
- .
Luster : appearance of mineral surf. In
reflected light
- .
Streak : finely powdered mineral
- .
Cleavage : tendency of mineral to break parallel (VdW)
- .
Fracture : direction of
breaking(flat/unflat)
- .
Hardness
- .
System
- . Habit
Crystal
systems: 6 basic crystal system
1.
Cubic
2.
Tetragonal
3.
Orthorhombic
4.
monoclinic
5.
triclinic
6.
hexagonal/trigonal
Crystal
Habit :
Single mineral :
Cubic,
prismatic, bladed, acicular, capillary/filiform
Aggregates/group of
crystal :
1.
Massive :
barite,pyrite,ilmenite,malachite,
3.
Botryoidal : hematite, malachite
6.
Columnar/euhedral :
beryl,apatite,corundum,aragonite
9.
Prismatic : barite,sphalerite
Luster
:
Metallic
:pyrite,galena, hematite,ilmenite
Submetallic : magnetite
Resinous
:sulphur,sphalerite
Adamantine :
cassiterite
Greasy/Silky : gypsum,
talc,graphite
Mohs
scale : (1-10)
Talc,gypsum,calcite,fluorite,apatite,orthoclase,quarts,topas,corundum,diamond
Crystallography
:
Diad (2-fold) -2 faces,
2 times similar faces found—triad---tetrad---hexad
Parallel planes :
CENTER
PLANES OF SYMMETRY :
CUT INTO MIRROR IMAGE