Jamison Brizendine
Meg Streepey
Senior Independent Project
18 April 2006
Mineralogy has been an important part of our everyday lives. We encounter rocks
and minerals everywhere we go, where we work, and where we relax. Your house for
example may have a cement roof, made up of the mineral gypsum. Your countertops may
be composed of granite, formed from the inside of a giant volcano. You may work in an
office building. That office building may have limestone facing which was the home to
an extensive and ancient coral reef. When you go to a beach to relax chances are the
beach is made up of quartz sand. Mineralogy exists everywhere and is a fundamental part
of geology.
In Physical Geology classes many students will learn how to identify minerals by
their basic physical properties. The physical properties for minerals are: luster, color, heft,
habit, cleavage, streak and hardness. Some minerals have a certain property which will
stand out easily. Halite, for example, has a salty taste, sulfur has a bright yellow color and
smells like rotten eggs, and magnetite is magnetic. Other minerals can be identified by
using only one physical property. Talc has a hardness of one, biotite, a mica, has one
perfect cleavage and its sheets can be peeled like an onion, and galena, is dense because it
has lead in its structure.
Unfortunately not all minerals can be identified with using one or even two physical
properties. Pyroxenes and amphiboles, a single-chain silicate and a double chain silicate
respectively can be difficult to identify in hand samples. They may share the same color,
habit, luster, and even hardness. The way to tell those two minerals apart is that
pyroxenes have ninety degree cleavage planes, while amphiboles have a sixty degrees
and one hundred twenty degrees cleavage planes. Another interesting example of mineral
confusion is the one between quartz and fluorite. Suppose someone finds a purple mineral,
it can either be an amethyst, a variety of quartz, or a fluorite. Quartz can be identified by
its superior hardness and its lack of cleavage. Additionally identifying plagioclase
feldspars and orthoclase feldspars can be very difficult for some students. Both share all
the same physical properties; however plagioclase feldspars are usually restricted to more
mafic rocks and orthoclase can be easily identified in most felsic rocks.
By learning about certain minerals the geology student can also learn about how
they form from the different environments in which the mineral formations take place. A
geologist would never find a diamond in central Indiana, just like limestone would not be
found in the interior of a volcano. A student would be able to find calcite readily in a
limestone, and quartz in sandstone. They may also learn that some minerals, like fluorite
and gold, are formed in hydrothermal veins. They may also learn that some igneous rocks,
like granites, would contain mostly plagioclase feldspar, quartz and orthoclase feldspars.
What if the student was not interested in geology? Why should they care about
mineralogy? The average person does not care about the effects that mineralogy has upon
their lives. In the sixteenth century, finding mineral resources was the result of
colonization, mining, warfare and the rise and fall of powerful empires. The Aztec empire,
for example, was annihilated because of the Spanish Conquistadors looking for gold.
After seizing all the gold, many of the Aztecs were slaughtered and a powerful empire
was reduced to ashes.
Mineralogy is used in many other sciences as well. Mineralogy contributes to the
study of chemistry, biology, astronomy and physics. In chemistry, minerals are entirely
elements and molecules. Elements have been successfully isolated from minerals. In
physics, mineralogy is used for the study of chemical tracers, and the understanding of
the origin of mineral phases. In astronomy, minerals have been used to calculate the age
of the Solar System, the Earth and the other celestial bodies that orbit the sun. Without
minerals, astronomers could only guess at the age of the earth, but with meteorites,
astronomers can successfully find the age of the solar system. In forensics, geology and
mineralogy is used to solve cases involving murders, rape and theft. A direct result of the
study of mineralogy was the development of forensic geology.
Forensic geology was first published as a method for solving cases in 1893 by
Hans Gross. Gross was an Austrian criminal investigator who had stressed the need to
use the microscope and mineralogy to examine the evidence left behind on shoes and
other pieces of clothing. Another person to pioneer the use of forensic geology was the
famous author who created Sherlock Holmes; Sir Arthur Conan Doyle. Doyle’s famous
character used his spyglass to find evidence from mud and soil to help locate his suspects
and solve the case. It would be only a matter of time before these methods would be put
to use outside of a fictional novel.
In 1904 Georg Popp, a German forensic geologist was the first person to use
mineralogy and forensics to solve a murder case. Inspired by both Gross and Doyle, Popp
examined the evidence left behind from a scarf that was used to kill Eva Disch, a
seamstress. The suspect, Karl Laubach, worked in a gasworks company and a gravel pit.
The scarf had snuff, coal particles, and the mineral hornblende. Popp then used the
suspect’s fingernails to try and find a match. Both the evidence from the scarf and the
evidence from Laubach fingernails was enough proof to sentence the suspect. With the
success of the Disch trial, other countries began to use forensic geology, including the
United States. In 1935 the FBI had a large amount of soil samples and three years later
had a large collection of metals and minerals to help solve more cases (Murray 2004).
Today the FBI solves thousands of cases each year using metal and soil samples, sand
samples, minerals and microscopes.
Many forensic geologists today use mineralogy and soil science as a tool. They
first tend to look for unusual or rare minerals. If they can identify these minerals, then
they can usually find where they originated. They can also use soil grain sizes and
combinations of minerals to help locate a source. Many times, forensic geologists are
unsuccessful and are frequently disappointed in their findings. This may be due to the
fact that there was no transfer that had taken place or soils may have been transferred,
resulting in a composite sample. Sometimes the area has had rapid soil change or there
was not enough soil to make an accurate conclusion. Suspects have been known to wash
the evidence behind so that there may not be enough evidence for a conviction.
Sometimes the suspect was not even at the crime scene, so in that case the soil sample
would prove his innocence in a crime.
The goal of the assignment was to create a forensic geology lab that would be
interesting and scientifically relevant for students. In order to create such a lab, it was
assumed that the students already knew basic mineralogy identification. The lab would be
designed to fit the student; not too simple, but not so challenging that it would frustrate
students who have trouble grasping basic mineralogy and science. The lab should also not
take longer than the average lab time, but also should take longer than an hour to
complete.
The creation of a good lab also needed an interesting plot. The first idea for the
lab was a murder case involving a deceased husband. The husband was the owner of a
large mineral collection and had been murdered so that one of the suspects would inherit
his collection. The story involved fifteen suspects and an inspector who had three hours
to solve the case before it leaked to the press. The story while cute had its own set of
problems: The first problem was the story was not serious enough for the students. The
second was finding fifteen samples that could be used in finding the murderer and the last
problem was that chances are the lab would have taken longer than three hours to
complete. The lab had to be rewritten and a new approach was taken.
So the new lab would also be a murder case, but a case that was documented and
could be used for a case study and good introduction for the lab. The murder of Adolph
Coors III was such a case. The Gravel Page, by John McPhee, was used to given the
overall background for the murder case. Adolph Coors was the grandson of the founder
of the Coors Brewery Company.
One day, no one knows for sure, he had disappeared from his ranch near Morrison,
Colorado. Morrison is near Denver, Colorado close to the foothills of the Rocky
Mountains. His car was found with the motor still running. Investigators also found glass
and blood around the car. A suspect’s vehicle was found near a dump site in Atlantic City,
New Jersey and showed four layers of earth material. The first, outermost, layer was
obviously soil from the dump. The three other layers matched the geology of the Rocky
Mountains. The sharp pink potassium feldspars came from the Pikes Peak granite, and
pink feldspars from other Front Range granites. Other samples were quartzose sands from
the Dakota Group and limes and clays from the Morrison Formation. One layer was
where the victim was found, which had contained the feldspars from Pikes Peak and
Front Range. The second layer of the three was the quartzose sands where Coors’s Ranch
was located. The final and third layer from the Denver area that had contained the clays,
sands and limes (Murray 95-96). The suspect, Walter Osborne, his alias name, was then
found guilty of kidnapping and murder because the suspect’s automobile was directly tied
to the crime scene and sentenced to life imprisonment.
The lab involved an event similar to this case. A truck was found in a parking lot
in Las Vegas, Nevada. Sand and gravel had accumulated on the tires of a vehicle and then
was sent to a lab for investigation. As the forensic geologist the student would have to
examine six samples given to him or her. Then the student was given an unknown sample
to look at, this unknown sample was a combination of three samples, and this was the
sample found on the truck tire.
Originally I had asked the students to identify the minerals in each sample, the
overall sorting of the sample, the average roundness of the grains, the average sphericity
of the grains, if there were foreign objects in the grains and to find fossils if there were
any. I had used six samples: The Sleeping Bear Dune from Traverse City, Michigan, The
Petroglyph Beach from Arizona, The Morrison Shale Formation from Arches National
Park, Arizona, Hilton Head Island Beach Sand, South Carolina, sand from the AuSable
River in the Adirondack Mountains of New York and sand from the Cove Creek in
Magnet Cove, Arkansas. All the samples were unique in appearance and had different
enough properties that the student could enjoy and not become easily frustrated. The
Hilton Head Island Beach sand had clear quartz, while the Petroglyph Beach sand had
iron-stained quartz grains. The Cove Creek sand had pyrite and magnetite in the sample
while the river sand from the AuSable River contained black hornblende grains and
bright red garnets in the sample. The Morrison Formation sample had green shale and
clays in the sample, while the final sample from Sleeping Bear Dune had iron stained
quartz, basalts and chert.
Doing the preliminary tests for the lab proved to be a little difficult for a student’s
level. It would be assumed that if this was done late enough in the year, and this time it
was, the knowledge of mineralogy would be a difficulty. I had created a Power Point to
demonstrate how to identify roundness, sphericity and sorting to the class. It was quickly
discovered that the students would have had a difficult time trying to figure out a grain’s
sphericity or overall shape. Additionally there were not enough fossils or even foreign
objects in the samples to make an accurate answer. To make the lab easier, the students
were asked to identify the overall colors in a sample, and then identify the average
roundness in a sample. The student was then asked to complete the sorting of the sample
and then finally the overall character of the sample. These questions were asked for all
six samples. Finally the student was to look at the unknown sample, and try to identify
the three samples found on the tire truck. He or she then had to plot the points on a map
to the possible route the truck had taken. These questions were sufficient enough to
challenge the student, but not to make it too challenging and it was thought that the
student would be able to complete the lab in less than three hours.
Appendix 1:
Jamison Brizendine
Meg Streepey
Physical Geology Lab and Independent Senior Project.
Everyone is quite familiar with Sherlock Holmes. Sir Arthur Conan Doyle created a
character that everyone would idolize. Holmes and his assistant worked for Scotland
Yard. They would go to scenes of crimes looking for evidence such as soil samples, paint
chips, wool and other material that would transfer or leave a presence. Forensic scientists
today are much like Doyle’s imaginary character. When they are called in to crime scenes,
they investigate reports and evidence. Today forensic geologists study material that is
transferred from one thing to another. Minerals, soils, glass, cement, asphalt, and other
foreign objects are used in their investigations.
Forensic geologists are called in for a variety of different crimes including theft,
murder, hit-and-run accidents, larceny, and kidnapping. Forensic geologists have worked
on cases ranging from rape trials, to finding thieves who have stolen thousands of dollars
worth of palm trees. Some forensic geologists even try to solve cases that involved
swapping traded goods.
A famous example that many forensic geologists are familiar with is the one that
involved the murder of Adolph Coors III. Adolph Coors was the grandson of the founder
of the Coors Brewery Company. One day, no one knows for sure, he had disappeared
from his ranch near Morrison, Colorado. Morrison is near Denver, Colorado near the
foothills of the Rocky Mountains. His car was found with the motor still running.
Investigators had also found glass and blood around the car. A suspect’s vehicle was
found near a dump site in Atlantic City, New Jersey and showed four layers of earth
material. The first, outermost, layer was obviously soil from the dump. The three other
layers matched the geology of the Rocky Mountains. The sharp pink potassium feldspars
came from the Pikes Peak granite, and pink feldspars from other Front Range granites.
Other samples were quartzose sands from the Dakota Group and limes and clays from the
Morrison Formation. One layer was where the victim was found, which had contained the
feldspars from Pikes Peak and Front Range. The second layer of the three was the
quartzose sands where Coors’s Ranch was located. The final and third layer from the
Denver area that had contained the clays, sands and limes (Murray 95-96). The suspect,
Walter Osborne, his alias name, was then found guilty of kidnapping and murder because
the suspect’s automobile was directly tied to the crime scene and sentenced to life
imprisonment. A more detailed reading to the Adolph Coors kidnapping and murder is
found on pages 91 to 102 in The Gravel Page, which you will be required to read before
coming to lab.
This lab will be very similar to solving the murder of the Adolph Coors case. The FBI
field office in Las Vegas, Nevada currently has a suspect with a warrant for the arrest of a
man who had recently shot and killed someone. The forensic geologist in charge of the
case is currently on vacation in his penthouse in Palm Springs, California and has asked
you to solve the case. The FBI has also found a car that was found in a parking lot in
Nevada that contained sediment from its tires and tailpipe. Your lab has received six
samples of various different locations and they want to know where the vehicle has
traveled. You are a given an unknown with three different sediment locations which you
will receive after analyzing the initial six samples.
A. References needed for lab:
1. The handout from Sedimentary Geology (Prothero and Schwab, 2004)
2. The Gravel Page by John McPhee
3. A handout from Ron Parker’s Sedimentology class, August 2004.
B. Please answer the following questions for the initial six samples:
1. What are the average mineral percentages in each sample? For example a sample may
have 50% of a reddish mineral and 50% of a clear mineral.
2. What is the overall general character or appearance of each sample
3. The average roundness: The roundness or angularity of grains.
4. Sorting: Are the grains well sorted or poorly sorted?
5. For extra credit: Name the minerals present in each sample.
Procedure:
1. Make groups of two to three people to share microscopes. There are six initial samples
available that were collected by your lab. Answer the above questions on the worksheet. I
will show you in class a step by step approach if you have trouble answering the
questions.
2. Take a small clear dish, and then take a very, very small portion of the sample, about
the size of you fingernail. Any larger and you will not be able to see the samples because
the grains will be to close together to see any detail.
3. After finishing with the sample you have looked at, dump the sample back into the
containers where they were found, this is so that they can be used later. Then clean the
dish with a damp tissue rag so that your new sample is not contaminated.
4. The samples come from the following sources:
Sample A: Dune Sand, Sleeping Bear Dune, Traverse City, Michigan.
Sample C: AuSable River, Adirondack Mountains, New York
Sample D: Petrograph Beach, Glen Canyon, Arizona
Sample F: Arches National Park, Morrison Formation, Utah
Sample G: Cove Creek, Magnet Cove, Arkansas
Sample I: Beach Sand, Hilton Head Island, South Carolina
5. Conclusion: In order to finish the lab, please write on a separate piece of paper of
which three samples were found on the truck tire. Explain how you came to this
conclusion using the data you collected. On the map of the United States, trace the route
the vehicle took from its origin to its final location in Nevada. Please turn this in with the
data you collected from your initial six samples.
The lab proved to be a large success and both lab classes thoroughly enjoyed it.
The students learned a variety of skills after completing the lab. One of these skills was
identifying minerals in a variety of sediments. Students were asked to identify various
shades of colored minerals, and then were asked to identify them. The purpose was that if
students could identify two physical properties: Luster and color. After these properties
are identified then finding the correct mineral would not be a challenge. Quartz, for
example is prevalent in beach environments, is non-metallic and it is a clear or orange
color. Students were also asked to find the general character of a sample. If a student
looked at sediment from Hawaii and then looked at sediment from South Carolina, there
are many differences. The Hawaiian sediment contains olivine, pyroxene, hornblende and
perhaps some quartz. The South Carolina sand is much more mature, it only contains
quartz and maybe bits of asphalt from a beach road nearby. Students would learn that all
sand, soils and sediments are not homogenous, but reflect on the depositional
environment.
Students also learned about the sorting, maturity and roundness of grains in
sediments. They found out that if the grains were angular and poorly sorted, then the
sediment must be near the source of original deposition. A sediment that contains grains
that are fairly well rounded and well sorted means that erosion processes are more
vigorous in that location. Some students also reviewed how some minerals are more
prevalent and resistant than other minerals. Olivine which forms first from Bowen’s
Reaction Series, typically is the first mineral to be destroyed by weathering processes
because it is unstable at the surface. Quartz on the other hand is highly resistant to
erosion. Quartz is harder than olivine and has no weak spots in its structure. The lab was
also intended for students to refresh themselves to identify minerals that may have been
tricky to identify earlier in the semester.
After completing the lab, students were asked to complete a survey and then
asked for questions or comments to help make the lab more enjoyable. The first question
asked the degree of difficulty of the lab. One hundred percent had commented that the lab
was just right for the skill level for physical geology. Other comments included that the
difficulty was well explained, challenging, and fun. Some students commented that the
lab was too simple because the samples were so different, and others thought it was a
little overwhelming to identify colors.
The next question on the survey asked the classes if the time of the lab was too
short, too long, or just about right. Ninety seven percent of the class said the lab was just
about right and only three percent of the lab group said it was too short. Other comments
included was that the lab did not have the feeling of being rushed and “didn’t eat away
my sunny afternoon”. Others felt that the outside reading of John McPhee’s article was
taken into account on the length of the lab. One comment was that long labs tended to be
redundant and that it would be hard focusing on the tasks at hand. This lab was short and
the questions were clear and concise. Another comment was that the lab could have asked
for more samples, but this one had shown enough differences in the different deposition
environments in the United States. The majority students had felt that the lab was a little
too short, but that if it had taken any longer than it would have become redundant.
The third question asked if the introduction and the explanation of the lab was too
brief and contained not enough detail, or it was too long and contained too much detail or
if the lab was just fine. The numbers had more variety here. Five percent of the students
felt that the introduction and explanation was too brief, eight percent thought it was too
long, and eighty five percent felt it was just right. Other comments included that there
was too much background information, such as the handouts, others felt that the example
in class was good, it was doable and straight forward, and that the case study was an
overall good introduction to the lab.
The final question asked if the lab furthered the student’s interest in forensic
geology, had no change on the interest in forensic geology or made the student wish they
had never heard of forensic geology. Fifty seven percent said that after doing the lab the
students were further interested in the study of forensic geology and twenty six percent of
the students answered that it had no change on the study of forensic geology. One person
commented that they thought about pursuing forensic geology as a possible career path.
An interesting question that was given to me was how one would know the order
of the places traveled. In the case of the current lab, this could not be done, because
samples were mixed with other samples to obtain an unknown sample. One way to solve
this question would be to have two unknowns. One unknown would have a mixture of
two samples and another unknown would have a mixture of the same two samples, plus
another sample to yield a final mixed sample. If that process were done, than the student
could draw a possible route on a map that the “vehicle” might have taken.
The overall results from the lab proved to be positive and beneficial for the
students, lab assistants and the professor. There should be no need to make any large
scale changes to the lab, since the students felt it was just right for the skill level. The
background reading for the class I felt was essential because it set the student up for the
lab. Without the background reading and case study, the lab would not be as interesting
or stimulating to students. If any changes were to be made I would make the following
changes: The first change would be to increase the initial samples from six to eight. The
two additional samples could be similar to each other, similar to the original samples, or
even very different from the original six. Making eight original samples and one
unknown would make the lab a little longer, but not make it so long that it becomes
redundant.
The forensic geology lab was a great choice for teaching students about possible
career paths, and a good introduction into sedimentology. It also engages the students to
identify minerals and look for objects they would not initially find in sediment, such as
cement, wool or asphalt. Using this lab is a great way for students to refresh themselves
on how to identify minerals and to teach students how geology is used in other
applications besides academia.