hi welcome to the introduction to
mineralogy this is the same basic
lecture that you would get the first day
of class we were meeting face to face
short overview go over some background
material kind of let you know where
things are gonna be going this semester
that's a fantastic photo isn't it
that's Mexico's Cave of the giant
crystals in Chihuahua it's in a mining
district and when they were drilling for
lead zinc they came upon this big cavern
in the year 2000 though some of those
crystals are 40 feet long and you can
see a guy over here standing and looking
this thing's actually full of water most
of the time hot water to over 50 degrees
C but anyway it's a limestone cavern
it's built in limestone anyway but then
hot waters got in there and sulphate
rich and have precipitated these giant
gypsum crystals pretty cool okay well
the learning objectives for this module
are gonna be we're gonna briefly discuss
the importance of minerals to geology
and of course society I mean this is the
reason you're taking mineralogy and
mineralogy is a required class at any
University that offers a geology major
because minerals are fundamental to the
birth growth development of the planet
rocks I mean you know humans use them I
mean it's it's everywhere so very
applicable material we're gonna list and
describe the definition of material
right a definition of a mineral we're
gonna we're going to talk about what it
means to be a mineral briefly describe
the course organization so you guys can
see why I'm teaching you what I'm
teaching you my rationale explain how
minerals are named briefly and uh and
then explain finally how mineral main
mineral groups are classified how are we
gonna break these things up you ready
okay so why study mineralogy well the
simplest reason is that
are the building blocks of rocks right
there rocks are just collections of
minerals for the most part and so if we
understand how minerals form then we can
understand how the planet forms and so
in this series of diagrams I've got the
entire planet Earth here and you can see
there's the oceans and there's the
continents and if we zoom in on the
continent you'll see that we get these
big outcrops and of course they're made
of different kinds of rocks but if we
zoom in on the outcrop in this case we
zoom in and we notice that it's made of
granite right it's the rock granite well
the rock granite of course is an igneous
rocks these minerals crystallized out of
a magma but when we look at the
individual minerals that what's causing
the color in this rock we see that we've
got a collection mostly of quartz
hornblende also there's going to be by a
tide in there and then the mineral
feldspar we can have one or both right
there there's two kinds of feldspars
there's plagioclase feldspar and there's
alkali feldspars potassium feldspar so
what if we like to call-- case bar
anyway so if you want to understand how
the planet formed you got to know where
these minerals came from so one of the
first lectures after this intro will be
to talk about chemistry because if we're
going to talk about where minerals come
from they are chemical compounds and of
course we have to understand why they
want to form in the first place so
that's enough for us right I mean we
understand that that that rocks are the
you know minerals are the building
blocks of rocks and if we want to
understand I'm a petrology right I'm an
igneous petrology which means I deal
with the formation of igneous rocks both
volcanic and plutonic
but when you're talking to your mom or
your cousin or your neighbor or whoever
right minerals are important to
everybody and you know they are a huge
economic value to civilization and it
that that's pretty well shown by this
bumper sticker down here that says if it
can't be grown
it must be mined and whether you're a
fan of mining or not it doesn't really
matter because we need to source these
raw materials from somewhere and
understanding the kinds of products that
civilization uses will lead you to
worldwide mining so when we look over
here at some household items right we've
got a thing at tums here which of course
helps after a hardcore Indian meal or
whatever might have upset your stomach
and in tongues are really just calcium
carbonate they're just limestone the
mineral calcite ground up a little bit
of sugar in there right some kind of
binder but for the most part it's just
calcium carbonate and you you take this
to counteract right acid just like when
you put acid on to identify calcite or
limestone right it reacts and this is
all this these tongues are doing when
you put them in you so somebody is just
mining limestone grinding them up and
turning them into tums of course here's
a salt shaker and of course salt is
coming from you know halite right and a
huge commodity boy if you want a really
good book read the book salt that's its
name and it'll tell you all about
through history and how the world was
basically run on salt we're getting it
transporting it right that kind of thing
huge huge big deal in the the
development of the human race that's the
the use of salt for preservation not not
only to make you know awful stuff taste
better but look even look at the
container the salt is in right this
chromed metal cap and the glass
container all stuff that had to be mined
we could over here to the pencil of
course that lead quote-unquote is not
led thankfully it is graphite and
graphite is carbon one form of carbon so
again if you're gonna make a pencil you
got to have some graphite and up here
you see the little metal band that's
probably steel of some type that has to
be mined as well
then a classic flip phone but if we look
at what's inside a phone a cell phone
you can see that there's all sorts of
different materials in here right silica
copper silver lithium iron and then of
course some petroleum stuff too so gonna
make a cell phone you got to dig a hole
in the ground and pull stuff out so I
think for many people on the planet if
you don't care about how the planet
works or the rocks right you do care
that you get your materials and if and
if you can't grow it like a tree or
cotton or hemp or whatever else you want
to grow right you got to mine it so this
is very applicable even though we won't
be talking about the economic type
minerals really but but you should at
least think about this um industry
health and hobbies well let's start with
hobbies so over here somebody's got a
swanky entryway to their home and here's
a giant amethyst quartz a sort of Geo
that it these come out of Brazil and I
don't know what's causing them they're
their big cavities and volcanic rock
with these hot gases and fluids that
pass through them and they played out
these large amethyst geode like
structures anyway people are buying
these lots and lots of minerals get
purchased just for decorations people
think they're cool alright so you have a
mineral collection their hobbies
industry ok so what this is this is a
zoom in this is zoomed in on a volcanic
rock and this was a vesicle right a hole
like in a volcanic rock like basalt and
it's now filled with a secondary mineral
this mineral didn't grow in the magma
all right it grew the magma was erupted
it crystallized it solidified it
crystallized right and and there was a
hole in there a gas bubble so it's a
vesicle like the holes you wouldn't see
in bread from the yeast and the key and
the gas is expanding ok then once this
rock is buried and it's subject to
groundwater passing through it and
fluids right
this mineral which is a zeolite right
zeolite and this zeolite mineral when
it's crushed up
it just looks sort of like kitty litter
and in fact kitty litter here's a kitty
down here probably a little too much
kitty litter in a box but one type of
kitty litter not all kitty litter is
made of zeolites but one type is there's
others that are made out of clays and
things but anyway so cat litter is a
zeolite product and what is so special
about zeolite swell the mineral it's a
it's it's it's actually classified as a
metamorphic mineral because it takes a
little heat not so much pressure but
heat to make them and you find them
beyond the the realm of diagenesis and
sedimentary rocks so it's not just like
a weathering product but anyway if you
zoom in and this is the picture here
this big amoeba looking thing that's a
an enlargement of a zeolite structure
and the thing that zeolites have going
for them is when they crystallize they
have these very large holes that are
left in the crystal structure there are
big pores so what you have to think
about is the zeolite is like a giant
sponge or or better a filter so when you
pass fluids that easily pass through
these crushed-up zeolites
and what happens is elements that you
don't want to have in the water get
stuck in the zeolites and the fluids
pass on through so over here I've got a
picture for you of a typical water
softener and a water softener contains
two tanks typically the one tank is just
full of zeolite so inside this tank and
this is this is these tanks can be three
four feet high they can be two feet high
depends upon how big of operation you
want but anyway you take your household
water supply and you push them through
these zeolites you just filter them
through the zeolite sand again they're
about crushed up like what's over here
in this hand and as that hard water the
water that contains
calcium and magnesium right from the
ground passes through those calcium ions
and the magnesium ions get stuck in the
zeolites and what ends up going into
your house then gets gets pushed through
here and then up this central pipe is
softened water
well eventually you have to clean out
the zeolites and this second tank is
full of salt and what it does is it
makes a brine when it's mixed with water
and then flushing these zeolites with
brine removes the ions that are trapped
in them and then it basically flushes
and makes the zeolites good again so at
my house my soft water operation
replenishes itself refreshes itself
cleans itself about once a week all
right
so zeolites which are an industrial
mineral easy to mine they're soft right
you use them for mostly for industrial
water filtration and things like that
they also work in kitty litter because
when the cat whizzes in the kitty litter
the the the pee is full of a big ammonia
molecules and those ammonia molecules
get stuck in the zeolites and of course
that helps to take care of the smell
neat huh okay well when I was looking
around for stuff to show you and make
this meaningful I also came upon this
company that sells this natural zeolite
powder and I was really intrigued so I
zoomed in and looked and it says it's
nature's best detox for radiation heavy
metals viruses and cancer relief and so
if radiation has kryptonite it's called
zeolites and you know that's not
complete nonsense because when you take
the large atoms the large radioactive
atoms like uranium and those sorts of
things they'll also get stuck sorc they
call it sorption into zeolites and so
they they sometimes line these
radioactive areas with a zeolite
material just in case anything leaks
it'll be sort up by the zeolite so I
didn't know that this would work in your
human body but they tell you so they say
you can detox heaven metals you can
smother viruses it shrinks cancerous
tumors mmm
makes your body highly alkaline so
disease doesn't want to be in there
restores lost energy hey you guys better
get some of the zeolite powder and take
it before mineralogy man
so restores lost energy and you feel
that mental fog lifting right and you
feel vibrant and energized Wow
and I thought it just helped with cat
whiz so anyway there you go
okay enough of that now let's look at
the definition of a mineral mineral is
naturally occurring in organic
homogeneous solid with a definite
chemical composition and an ordered
atomic arrangement which means its
crystalline alright so let's take a look
naturally occurring and inorganic okay
well here we go here's a lava flow in
Hawaii leaking out right and now it's
cooling and of course when it cools that
the atoms get together and form crystals
and so we see minerals crystallizing
from Magma's we also see minerals
crystallizing from water or fluids when
they evaporate right so so like this guy
says over here if you're not part of the
solution you're part of the precipitate
so minerals can be precipitated out of
the water they can crystallize out of
Magma's of course and also we can see
minerals precipitating or being
crystallized by organisms and with this
this doesn't violate the inorganic
aspect of that right because you know
when a shell an animal dies and it's
shells leftover they pile up to become
rocks so okay so in some places you have
a lot of sponges and corals and that
kind of thing so anyway there you go now
the naturally occurring part there's
many minerals that we can produce in the
laboratory right and these are synthetic
so so they're still like these this is
how you make a diamond okay this is a
a large diamond press and there's four
different sort of Rams that push in here
like four different presses that come in
all in this central point down here and
for scale you can see a guy's noggin
right here anyway you put a lump of coal
or a carbon little blob down there and
when you squeeze the the heck out of
this thing up the mantle white pressures
and temperatures you have to add
temperature to you can make a diamond
out of you know carbon and so over here
it's probably a little too small for you
to see but here's a little family right
and these two things that look like dog
turds are lumps of coal and there's mama
in the in the end and the daughter or
son I can't tell what it is anyway it
says and their revoir marking about
their father who's got the Hat on here
and he says well your dad's been under a
lot of pressure lately telling you that
of course when you take carbon in the
form of coal and you squeeze and heat it
to mantle like temperatures and
pressures you can turn it into something
new like metamorphism right and we can
get a diamond I was also researching
this sort of thing and came across this
company called life Jim and where you
can take your ashes your cat your dog
whatever and turn it into a diamond
pretty cool so um anyway most of the
diamonds that are made synthetically are
used in industry drill bits for cutting
through rocks tile saws you know you
name it right okay so nothing synthetic
but of course we can make materials in
the laboratory but okay now a
homogeneous solid so so so of course
minerals are solid right they're not
liquids they're not gases they have
cooled to the point where they are in a
solid state and what's meant by a
homogeneous is is that for more or less
the elements are are distributed evenly
right certainly they have their places
in these crystal lattices but you don't
find
one element on one side of a mineral and
different elements on the other side
it's more or less its homogenous and
it's a solid okay now it has to have a
chemical composition and I say definite
but but some minerals can actually have
can vary their chemical composition just
a little bit here and there and you can
also contaminate a mineral with other
elements and that's ok too and we'll
talk about that but but for the most
part here's a good example here's a
model of halite right there's there's a
there's a chunk of halide you guys have
all seen halite and if you put your
tongue on that it would taste nice and
salty anyway halide is made out of
sodium and chlorine right one-to-one so
the formula is NaCl and and you can't
put more na or you can't put more CL I
mean it is what it is right so in order
to be this mineral you have to have that
chemical composition and you have to
have this arrangement of them right if
you change the arrangement then you get
a different mineral if you change the
composition of course you get a
different mineral and a good example of
that is with graphite and diamond right
they're both made out of carbon but both
of them have very different crystal
structures right so anyway yeah so we're
gonna have a definite chemical
composition and I mentioned to you that
that every once in a while we can pop
one of these out like say we take of a
sodium out of here and we replace it
with a potassium that's okay we call
that substitution and many many minerals
do it because you know these minerals
aren't grown in purified areas I mean
some a lot of minerals are pretty pure
but many minerals have other
substitutions in there and of course
those caused some neat effects a lot of
times the neat color in minerals is
caused by the addition of some small
amount of an impurity again and there's
different ways that we can substitute
we'll get to that around lecture three
or so all right
so that's the definition of a mineral
now let's take a look at how the course
is broken down the first three weeks
okay so the first three weeks of the
class which is about 20% of the total
class we're going to be using the big
green book we call it right this book
has been around forever if you notice
it's the 23rd edition so you know I
don't know I think I took took this
class when we were probably in the 18th
edition or something anyway it hasn't
changed much they've added a lot more
material over the years it's gotten
better it's very expensive but you can
buy it used and you know I've never sold
mine because you know the the manual of
mineral science is not a text book like
you read it like a novel it's more of a
it's got data facts you look up minerals
you find out the details of different
minerals so it's a it's sort of a
glossary and a manual and everything all
rolled into one so here we are you are
we are in the introduction right now and
of course the second lecture for this
week will be the mineral chemistry
lecture I tell you over here k-means
this climb book right the green one and
it's going to be chapters 1 3 and 4 so
the first three weeks we're gonna cover
things like mineral chemisty up to
crystallography you're gonna have a
couple of problem sets you'll have a
quiz right the quizzes are gonna be
taken online and and they're just really
practice I just want to keep you up with
us I'm gonna make sure that you haven't
gotten too far behind and so what's
gonna happen every couple of weeks is
I'll give you a quiz
you're gonna download it you're gonna
fill it out you're gonna upload it back
in a blackboard right if those of you
that have taken a class from me online
similar okay that's gonna make sure you
can see the kinds of questions I would
be asking you and these will really help
you when it comes time for studying for
the exams okay what's next after the
first three weeks okay
then starting week four and leading up
to week nine we're going to be talking
about optical mineralogy
this is something
that's brand-new for everybody five
weeks the next 33% of the class okay and
what happens during this part is I teach
you how to use the petrographic
microscope
it's a polarizing microscope it's really
cool and it's gonna allow you to dig way
deeper into rocks and you can with a
hand lens and just using your eye okay
it's it's a little tricky but I've
gotten I've gotten hundreds and hundreds
of people through this before and you
will too okay I promise you you stick
with me you're gonna learn something
cool about minerals that you never knew
and it's gonna open up a whole new world
for you especially in petrology this is
why I've spent a third of the class
covering optical mineralogy is if you're
gonna go on to be a Patrol adjust
igneous metamorphic sedimentary you have
to know how to use the scope because all
the big details are down in there at the
microscopic level so five weeks for this
and of course your first lecture exam
will come at week five so I'm not giving
you anything else to do during those
lecture exams those lecture exams will
be proctored over in the e-learning
Center each one of you will make a
reservation and go over there at the
time you want during that week right
that works for you and you'll take this
exam okay then the third and final part
of the class is the final four weeks
okay and that is what we call systematic
mineralogy this is where you take your
knowledge that I've taught you in the
introduction and background you know
something about crystallography and
mineral chemistry you also know about
optical mineralogy and then what we do
is we look at the major mineral groups
that make up most rocks and these are
all silicates okay and you're gonna be
going over you know both enhance
specimen and in the microscope what's
going on with those mineral groups and
again this is back to both the the the K
book and the end book which is the Nesi
optical mineralogy book
so three five and four that totals up to
twelve where's the miss in three weeks
hey those are those three midterm exams
I was talking about and again these are
gonna be proctored through the
e-learning Center at UAA if you look in
the syllabus I've got a link in there
and what will happen is this as this
exam time gets closed you'll need to
make a reservation with them for a day
and time and you'll go in and Mel
Proctor and they'll give you the exam
okay all right so moving on let's talk
quickly about what it takes the name of
mineral man minerals have a wild wild
names and and and I don't know if you've
ever known or heard or why but anyway
you can use just about anything to name
a mineral and it's it's usually given by
the person who first identified them in
any way you see minerals names for their
physical properties
okay so olivine this is a common mineral
right olivine and this is olivine down
here it's named for the color olive
right olive like olive green the mineral
magnetite and here's some crystalline
magnetite it forms these little
tetrahedra and magnetite of course is
given the name because it's you guessed
it
magnetic some minerals here's chromite
and in chromite is named after a
chemical aspect of the mineral of course
chromite contains them a lot of the
element chromium and so it's named after
that many many many minerals are named
after where they are found so Franklin
Knight is from Franklin New Jersey
labradorite is from Labrador and and and
again you'll see a lot a lot of minerals
named after locations where they were
found
public figures these don't have to be
scientists but but many of them are
here's Smith's a knight oh there's
there's there's there's labradorite
right sorry I meant to mention that that
beautiful iridescent Labrador and of
course this is the shiny this is a
labradorite it's at
type of feldspar a type of plagioclase
feldspar anyway Smithson 8 is named
after this guy Smithson who was a
philanthropist of all anthropophagi
mothers and their Smiths tonight this
blobby sort of looking green stuff and
then finally the last example I give to
you is a very common metamorphic mineral
called sillimanite or you can call it
silly man it-- but it's sillimanite and
silliman was a noted mineralogist and so
here it is in quartz and what happens is
the sillimanite is these long rod like
fibers and it creates this sort of cat
eye effect when you polish it up okay so
there you go there's the ways you can
name minerals how about classifying them
any large collection and there's over
4000 minerals identified on earth and so
as soon as you start to a acquire more
than just a few of something you're
gonna want to figure out how to classify
them into different organized groups and
I've given you two examples here here's
somebody's butterfly collection so how
do you put the butterflies well I don't
know but it looks like he did it by
color here we've got some blue ones
we've got some orange ones we've got
some light colored ones I don't know
anyway you can do them by color and you
could certainly do minerals by color if
you wanted to now that's not gonna tell
you very much over here here's a guy's
giant car collection right and and and
if this thing is so big he's got
different rooms for different places
where they've come from this is the
English cars you'll see some Jaguars in
here right so these are the English cars
in this guy's collection so the point is
is you have to come up with some aspect
of your of what you are collecting to
allow you to classify it and with
minerals there's a couple of ways
okay that's Lila and she likes minerals
apparently anyway there's
crystallography alright in
crystallography what would be you would
use their crystal shape to to classify
them and and that means the ones that
look like little square
errors or pyramids or they're long and
slender right these this is the way if
you go to like the Smithsonian the
museum and you see a collections of
minerals they'll typically be displayed
by their shapes right hexagonal ones and
everything else which is really cool no
problem but with geology right we really
want to group the minerals together that
kind of form together so so instead of
using their shape right what we want to
use okay is their chemistry and and and
you know in chemistry right so so so in
rocks the minerals that typically grow
together and and so are the shape
doesn't help us and so you know we
rarely see quartz in its hexagonal form
we rarely see the feldspars with their
sort of box like form we see them all
mashed together in here right into one
big conglomerate so so using their
shapes is not going to really help us
but what really helps us is their
chemistry because minerals that are
found together tend to have similar
chemical properties so whether you're an
evaporite or whether you've formed in a
basaltic magma right you have things in
common so chemistry is going to be the
way to go for classifying minerals for
geologists and when it comes to breaking
down minerals into their major groups
right classifying in the major groups
we're gonna see silicate minerals versus
non silicate that's the big divisions
right shove silicate to one side non
silicate to the other and silicate
minerals turn out to be the most common
type of minerals on earth they are all
every silicate mineral has SiO 4 right
which is the silica techni formula for
the silica tetrahedra as its building
block so you have a silica tetrahedra
bonded to various cations to produce all
the different minerals and of course the
silica tetrahedra link
into different shapes but then you add
cations to it we're gonna talk about
that a little bit more in the next
lecture and then the next lecture after
that but every silicate mineral has SiO
4 that's the kimmel that's what they all
silicate minerals have in common is they
have this complex anion SiO 4 right as
their building block and why is that the
case why you know silicate minerals are
the most common group of minerals on the
planet and again never forget this the
reason that they're the most common is
because silicon and oxygen are the two
most common elements in the crust so you
dig up the crust you look at its
composition and you'll find that about
75% of the Earth's crust is just silicon
and oxygen oxygen being about 50% of
that silicon being about the next 25 so
it makes sense right if we're gonna make
minerals on earth they're they're most
likely going to be made out of silicon
and oxygen because that's the two most
common elements all right and when we
look at all minerals about greater than
ninety percent of Earth's crust is made
of silicate minerals so guess what what
do you think we're gonna focus on in
this class I can't talk about every
mineral but you know if you understand
how the silicate minerals work you're
good to go for most of Earth's crust so
when you take a look at this big pie
chart what we see is this big golden
color here is plagioclase right then
alkali feldspar right so just the two
feldspars together make up over 50% of
the Earth's crust and then you add
quartz in now you're getting even more
right so just this section right there
is just quartz and feldspar okay then we
come over here we've got the P Racine's
then we've got am four bulls right
Mika's clays and then the rest of the
silicates well look that's almost the
whole herbs right this last little pie
slice here right is non silicates that's
everything else so again if you ever
wonder
I am focusing on the silicate minerals
it's because that's the best bang for
the buck here non silicates if you're
not a silicate what are you well you
could be a carbonate that's the most
common non silicate mineral right
carbonates instead of having SiO 4 they
have Co 3 so if you don't if you're in a
place like Florida and there's no
silicates around you're gonna be
dominated by carbonates the halides
right that's like halite salt where
you're bonded to chlorine fluorine or
bromine you can have the oxides where
you're bonded to oxygen sulfides where
you're bonded to sulfur sulfates like
those big gypsum crystals in that cave
of the Giants in Mexico I showed you
that's so4 or you can have the native
elements you're not bonded to anything
you're just that element right metals
bonding to other metals all right so
silicates are what we're gonna focus on
now silicates get further subdivided
based on their internal order so this is
how we divide the silicates into
subclasses so what happens is that sio4
tetrahedra polymerize meaning they make
these long chains they make these
structures that look like like the space
station or something right these big
frilly complex structures all made out
of the silica tetrahedra and so the six
main groups of silicates are the nez o
silicates mezzo means island
sooro silicates or die silicates these
is the soro means Heep cyclo that's like
circle or ring I know which means thread
and these can be single or double Philo
means leaf these are the sheet silicates
like muscovite and biotite or finally
the tech toe and tech toe means the
Builder so these are these the most
elaborate silicates and these are also
called framework silicates so things
like quartz and feldspar we're going to
be going over these much more putting
things into the
different categories and you'll be
wondering well why does courts make a
techno silicate and why does something
like olivine make an Esso silicate over
here this ratio that's the silica to
oxygen ratio in these various groups so
we can see that in neso silicates we
have one silicon atom for every four
oxygens but then as we combine these
tetrahedra into these polymers right
these longer chains and things we reduce
the silicon oxygen ratio so here's a
panel taken from an intro lab book write
physical geology lab book showing you
these various different structures right
so here are the nazo silicates here's
the I know silicates right here's the
die of the double chain I know silicates
right
and here's sheet silicates and then
here's those framework or tech toh
silicates so you can see that it's these
tetrahedra linking up into these large
polymers and then the silicate minerals
are going to be divided into one of
these six classes alright well that's it
alright so next time the next lecture
we're going to discuss we're gonna go
into mineral chemistry and remind you of
things that you once knew like why do
these elements want to get together in
the first place what's gonna cause
bonding you know that sort of thing and
ultimately we'll actually get into
deeper into why do certain minerals form
certain ways and other minerals form
different ways it's going to be a repeat
of the general chemistry that you've
forgotten and it really nicely overlaps
with those of you that are in G Oak in
this semester because you'll be hearing
you know it coming from both sides cool
okay there's your little silica
tetrahedra right this is what the atoms
the atoms expanded so there's a four
oxygens and your one silicon atom right
and and there they all smash down right
making a tight fit and what's that
little plus four there and what's the
little two - well if you don't remember
that stay tuned to the next lecture
alright see ya