Lab 6!!
docx
keyboard_arrow_up
School
University of New Mexico, Main Campus *
*We aren’t endorsed by this school
Course
1110
Subject
Geology
Date
Dec 6, 2023
Type
docx
Pages
3
Uploaded by Brandygrace
Lab 6 – Minerals:
Gifts from the Earth
1.
Two common minerals that are often misidentified for each other are plagioclase feldspar and potassium
feldspar. Looking at both minerals, in what ways are they similar? In what ways are they different? What can you
use to tell them apart?
Plagioclase Feldspar:
https://skfb.ly/6SYYO
Potassium Feldspar:
https://skfb.ly/6S68C
These two minerals are similar in the fact that both have a glossy finish and the both present with a
range of colors. But Potassium Feldspar has a lot more of a red tint and ranging red colors, while
Plagioclase Feldspar is a white cream color. I think they are easy enough to distinguish between the
two just based on the colors of each of them.
2.
Two common minerals that are often misidentified for each other are amphibole and pyroxene. Looking at both
minerals, in what ways are they similar? In what ways are they different? What can you use to tell them apart?
Amphibole:
https://skfb.ly/6UtON
Pyroxene:
https://skfb.ly/6SW8W
Amphibole has distinct layers that can be seen, and it is very rigid. Pyroxene is also ridged. They both
have similar color schemes. I would be very difficult to tell the difference between the two without
having any other knowledge. Although Pyroxene does seem to look more like a granite.
3.
The samples in the previous two questions have mineral cleavage, what is mineral cleavage? How can you tell if a
sample has cleavage?
All of the minerals seem to have been broken with a straight and not jagged edge. While an opposing
side still is rough each of these have a clean flat break on another side.
4.
Quartz is one of the most common minerals, describe what quartz looks like? Does it have cleavage? What
unique properties does quartz have?
Quartz:
https://skfb.ly/6RzQJ
Quartz is not smooth but lumpy on every side. There Is not a smooth edge or break. Quarts does not
have any cleavage. Quarts is harder than glass and can have an electric charge which is quite unique.
5.
Quartz can often be found in many different types of colors, such as rose quartz, amethyst, citrine, etc. Why does
this happen? Can you rely solely on color to identify minerals? What else can you use outside of color to identify
minerals?
Color is very misleading because minerals can be found in many different colors. Quartz has many different color
variations due to other minerals getting mixed in and changing the makeup of that quart. Another way to make
to identify a mineral is to run it across a white ceramic plate and seeing the residue that is left behind.
6.
Sometimes color can be useful for identifying minerals, what is a way in which you can routinely identify this
mineral? (Hint, think about the name of the mineral)
Olivine:
https://skfb.ly/6TGo7
A way to routinely identify this mineral is by its color. It usually has an olive-green hue that makes it
standout compared to other minerals, and makes it hard to misidentify.
7.
Garnet often identified by its octohedryal crystal shape. How can you distinguish between a crystalline face and
cleavage?
Garnet:
https://skfb.ly/6qw6I
Crystalline and cleavage are smooth, but one have small break in it that the other one doesn’t.
8.
Two common minerals that are often misidentified for each other are muscovite and biotite. Looking at both
minerals, in what ways are they similar? In what ways are they different? What can you use to tell them apart?
Muscovite:
https://skfb.ly/6RMTF
Biotite:
https://skfb.ly/6TZMV
Both of these minerals are flat with rigid parts around the outside. But they do have a distinction in
color. Biotite is much darker in pigment than Muscovite is.
Muscovite has perfect striking for
cleavage that Biotite doesn’t have.
9.
Halite, Calcite, and Gypsum are three minerals that look similar? Looking at these minerals, in what ways are
they similar? In what ways are they different? What can you use to tell them apart? Do they have unique
diagnostic properties?
Halite:
https://skfb.ly/M8U8
Calcite:
https://skfb.ly/6UtDQ
Gypsum:
https://skfb.ly/6SZoI
All three of these minerals have a light white cream color to them. But Halite is the only one with a
shiny glossy finish. Gypsum is very dull, and has a lot of striking. Calcite is white but with red within is
has the step-like parts perfect for cleavage.
10.
Another mineral often mistaken for calcite by appearance is fluorite, how can you tell if a mineral is fluorite?
Fluorite:
https://skfb.ly/6TpTp
Fluorite is similar to Calcite at first glance. But it lacks step-like properties and is much darker in color
than Calcite. It has purple while, Calcite has red.
11.
Two common minerals that are often misidentified for each other are pyrite and chalcopyrite. Looking at both
minerals, in what ways are they similar? In what ways are they different? What can you use to tell them apart?
Pyrite:
https://skfb.ly/6TKJr
Chalcopyrite:
https://skfb.ly/6RFJE
I do not understand how these two could be misidentified. Based purely on there appearance one
looks similar to sand. With the appearance of a grain texture. While the other is glossy and appears
metallic. These don’t look anything alike.
12.
Two common minerals that are often misidentified for each other are galena and graphite. Looking at both
minerals, in what ways are they similar? In what ways are they different? What can you use to tell them apart?
Galena:
https://skfb.ly/HV8V
Graphite:
https://skfb.ly/6DOvt
Galena and Graphite are both dark grey. But Graphite has a metallic look and leaves a metallic
streak.
Galena has gold specks within the creases that are rather shiny but the rest of the mineral is
rather dull.
13.
Halite often breaks into square pieces, look at the molecular structure of halite to describe why it breaks into
these shapes?
3D model of chemical structure of halite, the larger green balls are Cl atoms and the smaller grey balls
are Na atoms:
https://skfb.ly/66rpT
Looking at the atomic chemical structure the mineral is built completely in a square form. The inner
make up is not circular or round whatsoever. The only possible way for it to break is into square
pieces.
14.
The composition of each mineral gives it unique properties. The orientation of the atoms also impacts the
properties of the mineral. For example, Graphite is very soft, so soft that we use it to mark paper (Typically we
refer to this as “pencil lead” because originally pencils used to contain a lead mineral Galena in them). In
contrast, diamonds are very hard, so hard that we use them to line things like drill bits and saw blades. Both
items have the same chemical composition, C, but have very different properties. Explain why graphite is softer
than diamonds?
3D model of graphite atomic structure:
https://skfb.ly/AOF7
3D model of diamond atomic structure:
https://skfb.ly/EG9W
Diamonds, makeup is much more condensed. And tightly knit together, where graphite is spread out
and has lots of room for movement in between atoms.
15.
Color is not always a useful property for mineral identification. The samples at this station are all examples of the
mineral hematite. Their different appearance is the result of the different environments in which they formed.
Nonetheless, every sample of hematite has one reliable diagnostic property that will always tell you what it is.
What is that diagnostic property?
Earthen Hematite:
https://skfb.ly/6utYX
Specular Hematite:
https://skfb.ly/6UqTP
Hematite is translucent which helps to identify what it is without misidentifying it for something
else. It also has a metallic luster that makes it slightly shimmer.
16.
Magnetite is our society’s other major source of iron. You are hired as a mine engineer to design a process to
extract magnetite iron ore out of a crushed rock. How would you extract out the magnetite iron ore?
3D model of magnetite:
https://skfb.ly/6AyyF
Video demonstration of magnetite with a magnet:
https://youtu.be/Yf9Q4fFyrcc
To extract the magnetite, they would place a magnate over the crushed rock and the magnetite will stick
to it, so it can easily be lifted away. It having a magnetic charge makes this process much easier.
17.
Although gypsum is no longer a component in most modern toothpastes, it is still widely used throughout our
society. The average American home contains tons of gypsum in the form of dry wall as it has flame retardant
properties. What about the chemical composition of gypsum (CaSO
4
· 2H
2
O) gives it theses flame retardant
properties?
Gypsum has water properties within which help to make the chemical compound fire resistant.
.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help