Mineral/Rock/Fossil Lab
This “mega-lab” is actually 3 labs in one that can be done simultaneously. You may come
to the lab anytime. Specimens are in the drawers against the back wall of lab. Take
out the drawers as you need them, then place then back in the correct space.
Your ultimate objective… is to be able to 1) tell whether a sample is a rock, mineral, or
fossil, then 2) identify by name any of these samples you are given, and to provide any of
the specific information required for each group of samples. (Charts are to help you. You
don’t have to turn them in.)
I. Minerals
Minerals are the building blocks for the rock material
composing the earth’s lithosphere. They have a specific
chemical composition and are identifiable by several
properties.
Objective…
Given one of the minerals, make a positive identification by examining its properties.
You may do any of the tests below to help you identify. You may also use your (and only
yours) MINERAL DATA CHART during the exam.
Materials and Methods…
Using the designated mineral specimens, determine the properties that will help you
identify it. Note that for each type of mineral there may be a range of colors, sizes, etc. in
one container. Don't worry about the extreme samples. Concentrate on what appears to be
the "typical" properties. Be sure to keep the specimens in the right container.
Color
Determine the designation for the closest match on the standard color chart (ex. A12,
M8).
Streak
Scrape the sample carefully on a streak plate and match the color on the standard color
chart.
Luster
This is the way the surface looks or feels. Is the luster METALLIC, EARTHY, GLASSY,
etc.? There are no right-or-wrong terms for this—use descriptions that are meaningful to
you.
Fracture/Crystal
This is the way the mineral breaks (don’t break them any more) leaving certain surface
features or definite crystal shapes. Use the crystal sample set to help you. If there is no
obvious crystal then choose one of the following fractures: CONCHOIDIAL,
SPLINTERED, FACETED, IRREGULAR
Hardness
Perform a Mohs test and estimate the hardness. This may be useful in differentiated very
similar minerals.
Other Properties
Magnetism – Does a magnet attract the sample?
Acid test – Hydrochloric acid fizzes when applied to calcium-containing minerals, such
as calcite and marble. Caution- Acid burns skin and eyes. Wash the acid off the sample
when you finish and dry it.
Fluorescence – Place the mineral under a UV lamp (blacklight). Some minerals glow in
different, but predictable colors.
Remember… I won’t grade your data chart or your ability to perform mineral tests. All
you have to do is tell me what the mineral is. Use the properties to help you identify the
samples.
II. Rocks
Objective: Be able to identify the following rocks by name, rock type, and other
descriptors as noted. You may use the ROCK DATA SHEET to help you study, but you
may not use it during the exam.
IGNEOUS TYPE (be able to distinguish aphanitic, phaneritic, etc.)
granite
rhyolite
obsidian
pumice
gabbro
basalt
SEDIMENTARY TYPE
sandstone
limestone
conglomerate
breccia
coal
shale
stalagmite
METAMORPHIC TYPE (be able to tell which rock these were metamorphized from)
gneiss
shist
marble
quartzite
slate
III. Fossils
Fossils are the evidences of living organisms that have been preserved in sedimentary
rock. They may be the mineralized remains of the organism or parts of the organism, or
artifacts made by the organism, such as foot prints or full body prints. For the following
fossil samples, be able to identify the fossil by name and tell the information cited.
Crinoids
These were relatives of starfish, living on the floors of shallow
seas. Fossil remains resemble rolls of Life-Savers candy,
usually with a 5-pointed hole. The animal consisted of a
holdfast, or pedestal that was attached to the ocean floor, with a
slender stem growing upward. At the top of the stem there was a
“head” that resembled a modern starfish. The center of this head
looks like a 5-sided acorn.
In these samples you will see stem sections, loose stem circles,
heads, holdfasts (large spheres), and whole specimens (display
case #5, bottom shelf).
Petrified Wood
This is what remains when all of the wood molecules in a chunk of ancient wood are
replaced by mineral crystals. The result is a precise copy of the original chunk, only in
stone. Often, you can see the prints of the grain and wood fibers clearly.
Bryozoans
These were colonial animals, meaning that they lived as a cluster. They secreted a
calcium-based pedestal to live on, similar to corals. The fossils seen here are the
pedestals.
Trilobites
Trilobites are a common, and popular fossil for collectors. All trilobite species are
extinct. The closest living relative of trilobites is the horseshoe crab. For whole
specimens, see display case #2 and #5.
Ammonites
Although this shell fossil looks like a snail shell, it actually belonged to an animal that
was more like an octopus. Similar to modern nautiluses, ammonites floated upright with
their tentacles extended from the shell.
Brachiopods
These animals were similar to modern clams and oysters except that they are symmetrical
from side to side rather than top to bottom. Brachiopods were sessile, meaning that they
spent their life attached to something. There are a few species of living brachiopods, but
the ones seen here are all extinct.
Pelecypods
This is a general term for bivalve, or 2-shell animals, such as clams, oysters, and mussels.
The name mean “axe foot” because of the shape of its soft parts. Compare these to the
brachiopods and note the symmetry difference.
Gastropods
This is a general term for univalve, or 1-shell animals, such as snails. The name means
“stomach foot” since the animal typically stuck its belly out of the shell to move around.
Worm Tubes
These fossils are actually the sediments that hardened inside of empty worm holes in the
sea floor.
Dinosaurs
Most of what remains of this most famous extinct animal group is bones. The reddish
samples are from a Mosasaur. The black samples are from a cat-sized dinosaur called
Captorhinus. Both samples were recovered in Oklahoma. Also, look at the joint-bone in
display case #1 outside of lab.
Captorhinus
Mosasaur
We tend to focus on the large dinosaurs like T. Rex, when most species that we know
were small like Captorhinus.
Corals
Like the bryozoans, coral animals secreted and formed their own base to sit on. Living
species today form the large reefs that are found in much of the ocean. Reefs provide
habitat for many other types of ocean life. The specimens you see here are extinct forms.
Ferns
These are well-preserved fern leaves in slate rock. They were found associated with a
coal vein in eastern Oklahoma.
______________________
MINERAL DATA CHART
Mineral
amphibole
apatite
azurite
biotite
calcite
carnatite
chalcopyrite
feldspar
fluorite
galena
graphite
gypsum
halite
hematite
magnetite
malachite
muscovite
olivine
plagioclase
pyrite
pyroxine
quartz
sulfur
talc
Color
Streak
Hardness
Crystal/
Fracture
Luster
Other
ROCK DATA CHART
IGNEOUS
crystal type
granite
phaneritic
rhyolite
obsidian
pumice
gabbro
basalt
SEDIMENTARY
sandstone
limestone
conglomerate
breccia
coal
shale
stalagmite
METAMORPHIC
derived from…
gneiss
shale
shist
marble
quartzite
slate
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