CHPTR 1/2 Minerals Flashcards
Mineral characteristics (5)
- naturally occuring
- solid at room temp
- regular internal structure of atoms (crystalline)
- narrowly defined chemical composition
- usually inorganic
polymorph + example
mineral with the same chemical formula but a different arrangement of atoms
ex. graphite vs diamond
habit + example
shape of intersection of equivalent crystal faces are identical on all samples of a particular mineral
quarts grows into that 6 sided shape
amorphous material
rigid substance without ordered arrangement of atoms
lustre
how “shiny” the mineral is
vitreous
glassy
dull/earthy + example
non-reflective - basalt
greasy + example
resemble fat or grease -obsidian
brilliant
light is reflected from within the gem
metallic
reflective in the same way that polished gold or silver is
colour
colour of minerals is often variable due to impurities. metallic luster have more consistent colour
scratch test of silicates
white streak
Scratch Test
magnetite
chalcopyrite
galena
goethite
malachite
azurite
hematite
sulphur
black
black
grey
yellow-brown
green
blue
red-brown
yellow
Moh’s hardness diamond
10
Moh’s hardness corundum
9
Moh’s hardness Topaz
8
Moh’s hardness Quartz
7
Moh’s hardness potassium feldspar
6
Moh’s hardness apatite
5
Moh’s hardness Fluorite
4
Moh’s hardness Calcite
3
Moh’s hardness Gypsum
2
Moh’s hardness Talc
1
Basal cleavage + example
1 plane - muscovite
prismatic cleavage
2 planes at 90 degrees - orthoclase
non prismatic cleavage
2 planes not at 90 degrees - amphibole
cubic cleavage
3 planes at 90 degrees - halite
rhombohedral cleavage
3 planes not at 90 degrees - calcite
octahedral cleavage
4 planes - fluorite
types of fracture + examples
irregular - olivine
splintery - asbestos
conchoidal fractures - curved surface
specific gravity
density
what mineral tastes salty
halite
what mineral tastes bitter
Sylvite
what rocks react with HCl
Calcite
Dolostone but not as much - needs to be a powder
why doesn’t dolostone fizz as much as calcite.
dolostone has nearly the same chemical formula as calcite. The difference is Mg in the dolostone
anisotropic
double refraction - calcite
sulphids anion
sulfer
sulphids examples
(the squares)
sphalerite
chalcopyrite
pyrite
galena
oxide anion
oxygen
oxide examples
(the cool features)
magnetite
haemetite
alumina/currundum
uranitite
halide anion
halogen
carbonate ion
(CO3)^2-
halide examples
(the salty ones)
Halite
Sylvite
Fluorite
carbonate examples
(the ones that react with acid)
calcite
aragonite
dolostone
how are aragonite and calcite similar. Which one is more stable
polymorphs
bifringent
calcite
sulphate anion
(SO4)^-2
silicate anion
(SiO4)^4-
what mineral class is olivine
single tetrahedra silicate
what mineral class is peryoxene
single chain silicate
what mineral class is hornblende
double chain silicate
what mineral class is biotite/muscovite
sheet silicate
all single tetrahedra, single chain, double chain and some sheet silicates are felsic or mafic
mafic
all 3D framework and some sheet silicates are felsic or mafic
felsic
what mineral class is potassium/plagioclose feldspar and quartz
three dimensional silicate
ratio of oxygen to silica in a single tetrahedra
4:1
ratio of oxygen to silica in a single chain silicate
3:1
ratio of oxygen to silica in a sheet silicate
2.5:1
ratio of oxygen to silica in a double chain silicate
2.5:1
ratio of oxygen to silica in a 3D framework
2:1
which is more dense, felsic or mafic silicate minerals
mafic is more dense
list minerals that are isolated tetrahedra silicates and what elements they also have (3)
forsterite - Mg between isolated tetrahedra
fayalite - Fe between isolated tetrahedra
olivine - Fe and Mg
another name for amphibole
hornblende
another name for pyroxene
augite
sheet silicate examples (2.6)
mica group - mica, muscovite, biotite
clay group - kaolinite, serpentine, montmorillonite
clay group silicates definition
sheet silica minerals with water trapped between sheets
formula of quarts and why it’s relevant
SiO2 - most silicates have the anion SiO4^4-, but the are continuously bonded in quartz
another name for potassium felspar
orthoclase
another name for plagioclase feldspar when it is has Ca
anorthite
another name for plagioclase feldspar when it has Na
albite
feldspars make up ______% of Earth’s crust
60
difference between plagiofeldspar and postassium feldspar (2)
plagioclase feldspar has striations, potassium does not
potassium feldspar is salmon pink, plagioclase is grey-blue
anorthosite
the rock from the moon. intrusive rock that contains >90% plagioclase feldspar
layers of the Earth as defined by chemical compostion
crust - felsic minerals
mantle - mafic minerals
outer core - liquid iron
inner core - solid iron
mafic
contains mostly Fe and Mg
felsic
contains mostly Na, Ca, Al (silicates) (not Fe or Mg)
types of crust
oceanic (thin and dense)
continental (thick and light)
Layers of Earth as defined by mechanical distinction/physical strength
Lithosphere - rigid outer layer
Athenosphere - semi-liquid (weaker) layer underneath
who is credited with proving plate tectonics
Alfred Wegener
divergent plate boundary and what they produce
plates move apart
continent -> rift valley
ocean -> mid-ocean ridges
convergent plate boundary and what they produce
plates move together
oceanic/continental -> subduction zone
continental/continental -> mountains + large plateaus
subduction zone
denser plate (oceanic) is pushed down underneath, bringing water into the mantle. This lowers the melting point of the rocks and creates volcanoes
transform plate boundaries and what they produce
plates move past each other
big earthquakes
transform fauls
offset mid ocean ridges on seafloor
what mineral is present the most in the Earth’s mantle and at what percentage
Olivine makes up 60% of the Earths mantle
what types of bonding occurs in a sheet silicate
covalent bonding within the sheets. Ionic bonding between
how is serpentine formed
metamorphism of basalt
how is dolomite formed
derived from shells/precipitates from seawater
what type of mineral are most rock forming minerals
silicates