Mineralogy: The Study of Minerals and their Properties • A Mineral…
! Occurs _______
! Is a _______
! Is a _______ substance (element or compound)
! Has atoms arrange in an orderly pattern (________)
! Is _________ (not formed by any process involving plants or animals)
• The most common elements that make up minerals are oxygen, silicon,
aluminum, iron, calcium, potassium, and magnesium
• There are over _____known minerals; most are _____.
• Common minerals that make up most of the Earth’s crust are called _____-
_______ MINERALS
• Most minerals are ___________
(i.e., halite = NaCl, Galena = PbS)
• A few minerals are made up of only ONE element, and are called
__________elements
(i.e., gold, copper, silver, sulphur, carbon)
Mineral Identification • Minerals are usually identified using _______ properties, although some
simple _________tests may also be used. IDENTIFICATION BY INSPECTION:
Colour
• First, and most easily ___________ property
• Some minerals have ___________colours (i.e., malachite, sulphur)
• However, many different minerals have _______colours
• ____________may also alter the colour of minerals
Lustre • The way a mineral shines in __________light.
• Either metallic (like polished _______) or non-metallic
• Non-metallic lustre may be further described as _______ (glass-like), pearly,
greasy, dull, earthy, etc.
Crystal Shape
• When minerals have time and room to form, their particles arrange
themselves into flat-faced, regularly shaped _______.
• However, most mineral grains are too small or imperfect to identify.
IDENTIFICATION BY SIMPLE TESTS Streak
• The colour of a mineral’s _______when it is rubbed against a streak plate
• Metallic minerals give _____streaks (brown, grey, black)
• Nonmetallic minerals give _______streaks
Cleavage/Fracture • A mineral exhibits cleavage if it breaks along flat _________ when hit with a
hammer.
• A mineral exhibits fracture if it splits into _______or _______ surfaces.
Hardness • A mineral’s _________to being scratched.
• Moh’s hardness scale: measure of how hard a mineral is compared to a
__________set of minerals, ranging on a scale from 1 to 10 (softest = talc
(1), hardest = diamond (10)).
• Prospector’s Scale: Fingernail = 2.5
Penny = 3
Steel = 5.5
Glass = 6
Specific Gravity
• The relative _______ of a mineral.
• Ratio of mineral’s weight to an equivalent amount of _______.
• Specific gravity of __________minerals is generally < 3
• Specific gravity of _________ minerals is generally > 5
Acid Test
• When calcite is exposed to _______, it fizzes
• Gas produced is _______dioxide
Magnetism
• Some minerals containing iron are _______ and will be attracted to a magnet
(ie., magnetite)
OTHER PROPERTIES:
Taste (i.e., _______ – rock salt)
Fluorescence (glows in _______ light)
Radioactivity
Double __________
Mineral Groups
• All minerals can be classified as either __________ or
_____________minerals
Silicates
• Silicate minerals contain atoms of __________ (Si) and __________ (O)
• Some only contain silicon and oxygen (i.e., ________), but most also
contain one or more other __________ (i.e., feldspar)
• __________is the most common mineral in the earth’s crust, followed by
__________
• Silicates make up ___% of the Earth’s crust
Non-silicates
• 4% of the Earth’s crust is made up of non-silicate minerals (meaning they
don’t contain __________)
• Can be further classified as:
o Carbonates – contain carbonate (CO3) group
o Halides – halogens (Cl, F) with Na, K or Ca
o Native __________
o Oxides – contain __________, but not silicon
o __________– contain sulphate ( (SO4) group
o Sulfides – contain __________
PETROLOGY
The Study of Rocks and their Formation
PRINCIPLES OF UNIFORMITARIANISM:
1. Geological processes now at work were also active in the __________.
2. Physical features of the Earth were formed by these processes over
______ periods of time.
In other words, the rocks we see around us were formed in the past by the
_____ geological processes we see around us today.
Rock Types and the Rock Cycle
• A rock is a __________of minerals bound together (i.e., it is usually a
__________).
• There are three types of rock:
1. igneous rock – formed when ________rock cools
2. sedimentary rock – formed from weathered and eroded rock that is
__________and ________ together into new rock.
3. metamorphic rock – formed when existing rock undergoes intense
_____ and __________ that alters the rock’s composition and
characteristics.
IGNEOUS ROCKS
• “__________” comes from the Greek word for fire.
• Deep inside the earth, the temperature is very high and the rock there is in
liquid form called ________.
• As magma pushes towards the Earth’s __________, it starts to cool and
turn into solid igneous rock.
• Igneous rocks that cool __________ deep in the Earth are called
intrusive or plutonic igneous rocks.
• Other igneous rocks form when magma erupts from a volcano, or reaches
the surface through long cracks in the crust. Magma is called _______
when it reaches the Earth’s surface. These are called extrusive or
volcanic igneous rocks.
• Igneous rocks are classified by __________ (the minerals it contains) and
__________ (crystal size).
Composition of Igneous Rocks
Igneous rocks form from two main types of magma:
• FELSIC: ! Magma with a ______ percentage of silica (SiO2) and little calcium,
magnesium or iron.
! Felsic magma is _______ and slow-flowing
! Forms _______-coloured rocks
! Most __________ rocks are felsic
• MAFIC:
! Magma with a ____ silica content, with higher amounts of calcium,
magnesium and iron.
! Hotter and ________than felsic magma
! Forms ________-coloured rocks
! Most __________rocks are mafic
Texture of Igneous Rocks
• Depends on ______ of mineral crystals in the rock.
• Crystal size depends on how ______ magma hardens
• LONGER = LARGER
• Plutonic rocks cool slower, therefore _______grains
• Lava hardens rapidly forming ______ crystals
• Lava that cools super-quick forms rocks with ___ crystals
• Porphyry: a rock with 2 stages of cooling, so that it has both _______
and ________ crystals.
SEDIMENTARY ROCKS
• most of the earth’s _______ is covered in sedimentary rocks
• there are three types of sedimentary rocks:
a. clastic - made from _______ of other rocks.
b. chemical - formed from precipitates falling out of _______.
c. organic - formed from remains of _______ and _______.
Clastic Sedimentary Rocks
• form when rocks _______ (break apart).
• That material is eroded (_______ away) and later _________ in another
location.
• Layers of sediment undergo __ _____and _________ to eventually form
sedimentary rocks.
• Clastic rocks are classified by “_______” (size of particles)
" Conglomerate: made up of _______ and sand
" Sandstone: mainly _______ of quartz
" Shale: tiny flakes of ____ cemented together
Chemical Sedimentary Rocks
• Form when sea, lake, swamp or underground waters __________ or
change temperature, causing dissolved minerals to fall out of solution.
• Examples include some __________, rock salt and rock gypsum.
Organic Sedimentary Rocks • Formed from the _______of plants and animals
• Shell-producing organisms such as clams, mussels or coral are made up
mostly of _______ – the mineral that makes up limestone. When they die
their shells pile up on the floor of the water body, and eventually
_______together to form limestone.
• Coal is formed from _______ plants that are buried and compacted into
matter that is mostly _______.
Metamorphic Rocks
• _______ and _______ can cause certain minerals to change into other
minerals.
• Mineral crystals may also change in _____ or _____, and may separate
into _______ bands.
• Hot _______ may circulate through a rock, dissolving some minerals and
depositing others.
Types of Metamorphism:
1. Contact metamorphism – when hot magma pushes through _______
rock, causing changes in the structure and composition of
surrounding rock.
2. Regional metamorphism – movement of tectonic plates creates
tremendous ______ and ______ at plate boundaries, changing
minerals into rock.
Classification of Metamorphic Rocks:
• Made according to the texture of the rock (foliated or non-foliated), and the
composition of the rock.
• FOLIATED:
o Extreme pressure _______ mineral crystals in rock and pushes them
into parallel bands
o Minerals of different _______ separate into bands, often producing
alternating dark and light layers.
o Examples included slate, schist and gneiss
• NON-FOLIATED: o No “banding” or _______ are observed
o Examples include quartzite and marble
o