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RVCC GEOL 157 Introduction to Geology
Professor Gregory C. Herman [email protected] Manual
GCH 2018-01
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Sources noted within
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
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• LAB ROOM SC-219 is set up with five (5) student tables with four seat each.
•One Fischer-Scientific stereo microscope will be furnished per table during mineral
and rock labs.
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PROJECTOR
LECTURN
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
LAB ROOM SC-219 is set up with five tables, four seats per table.
• Laptop PCs are available to students if they do not have one or cannot use their own.
Use of one’s own lap top is encouraged, as is the use of a optical mouse with a wheel
(USB or Bluetooth) for Google Earth labs.
Paired
wide-field
eyepieces
Adjustable
magnification
by rotating
the
adjustable
turret
Adjustable
left eyepiece
for focus
Adjustable
knob used
to lower and
raise the
microscope
head
stage
Fischer-Scientific T1A
STEREO MICROSCOPE
RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
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Can transmit
plain white
light from
above or
below the
object placed
on stage (light switches
not shown)
• This lab is an introduction to minerals and spectroscopy, the latter being the
scientific study of how light interacts with solid matter.
Minerals comprise Earth materials and are formed by :
1) the cooling of melted Earth material (molten magma) in Earth’s crust (solid) and
2) the precipitation of minerals from either
a) saturated, briny fluids (including microcrystalline forms of quartz and calcite) or
b) biological accretion (seashells)
By the end of this lab you should have a working familiarity with the most-common rock
forming minerals, including the 5 most abundant silicate rock-forming minerals (quartz,
feldspar, mica, amphibole, and pyroxene) that comprise Earth’s crust. We will identify them
separately from other common minerals that appear similar but are usually softer and formed
from precipitation .
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals and Spectroscopy
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Exercise 1. Handle and identify the 10
most common rock-forming minerals
Laboratory 2. Minerals
• Carbonates (CO3)-2
•Sulfates (SO4)-2
•Phosphates (PO4)-3
Calcite (CaCO3) is the
main constituent in the
sedimentary rock
limestone
Gypsum (CaSO4 . H4O) is a main
constituent in drywall
Turquoise CuAl6(PO4)4(OH)8·5H2O
derived from the shells and hard parts of marine organisms or are precipitated
as seawater evaporates
derived from hydrothermal activity or
are precipitated as saline-water
evaporates
derived from hydrothermal
activity and igneous processes
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Mineral Cleavage
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
http://slideplayer.com/slide/8711262/26/images/9/Types+of+Cleavage.jpg
Laboratory 2. Mineral Cleavage Types
Mohs Hardness Scale
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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Laboratory 2.
Minerals
Adapted from Cronin,
V. S., and Tasa, D.,
11th Laboratory
Manual in Physical
Geology: Pearson,
New York, NY, 426 p.
RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Silicate Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
Quartz – No. 2 of the 5 most common rock-forming (silicate) minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
• Identify quartz, calcite, and gypsum by checking the type of habit, cleavage,
and visual aspects that you observe
Quartz (silica SiO4)
Calcite (carbonate CaCO3)
Gypsum (sulfate SiO4)
NOTES:
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
• Group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust.
•Two cleavage directions at 900.
•Hardness of 6 – 6.5.
•Will not scratch glass or quartz.
•Microcline and orthoclase
•Not usually clear.
•Often salmon pink or white and milky.
•Can also be aqua blue.
•Can have wavy stripes of similar color that go through the mineral.
Alkali feldspars (K,Na)AlSi3O8
Plagioclase feldspars (Na,Ca)AlSi3O8
•Albite to Anorthite solid-solution series
•Individual crystals a range of colors between white and dark gray.
•Exhibits striations
•Can have wavy stripes of similar color that go through the
mineral.
www.earthguide.ucsd.edu/mystery_detectives/media/flash/minerals_igneous/minerals_igneous.swf
FELDSPAR – No. 1 of the 5 most common rock-forming (silicate) minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
• Identify plagioclase and alkali feldspar by color, microscopic twinning, and
mineral habit, hardness with respect to quartz and metal. Note any visual
and physical aspects that you observe.
Plagioclase feldspar (silicate (Na,Ca)AlSi3O8)
Twinning seen on face of large plagioclase sample
Alkali feldspar (K,Na)AlSi3O8)
NOTES:
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Cleavage habitLaboratory 2. Minerals
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Cleavage habitLaboratory 2. Minerals
• Identify the following minerals by color, and mineral habit, hardness with
respect to quartz and metal and one another. Note any distinctive visual and
physical aspects that you observe.
Mica (biotite and muscovite)
Pyroxene
Amphibole
Olivine/peridotite
NOTES:
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Laboratory 2. Minerals
Laboratory 2 – Part B Spectroscopywww.impacttectonics.org/Gcherman/downloads/PHY120C/
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
For this exercise, pick 3 minerals out of the box and use your manual and the Internet
to make your best guess as to what it is. Write the name and a chemical formulae down.
Color
Habit
Cleavage
Hardness
Weight
Streak
Magnetic
Notes:
Name
Chemical
Formuale
Sample 1 Sample 2 Sample 3
Laboratory 2. Minerals Pick 3 Exercise
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RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
Exercise 1. Identify the 10 most
common rock-forming minerals
Gypsum
(Alabaster) Muscovite
(mica)
Gypsum
(crystalline)
Calcite
(spar)Halite
Plagioclase
feldspar
Milky
quartz
Quartz crystals
Alkali
feldspar
(Orthoclase)
Pyroxene
(Augite)
Amphibole
(Hornblende)
Laboratory 2. Minerals
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1) Igneous are derived from the hardening of
molten magma (intrusive or volcanic, with felsic,
intermediate, and mafic varieties)
2) Sedimentary are derived from detrital or
chemical sediment, the products of mechanical
and chemical weathering and chemical
precipitation.
3) Metamorphic are the result of burial,
increasing temperature and pressure, and fluid
transfer processes during recrystallization
(low, medium, and high grade)
RVCC GEOL 157 Introduction to Geology Lab Manual GCH 2018-01
• Igneous rock forms when hot magma cools and solidifies. Sedimentary rocks form when
sediment is compacted and cemented together (lithified), or when minerals precipitate from
solutions. Mechanical weathering and physical breakdown of a parent material (usually rock)
produces clastic or detrital sediment, whereas chemical sediment is accreted through
biological processes or precipitates directly from hydrothermal or briny waters. Metamorphic
rocks are compacted, heated, pressurized, and altered from burial, thermal contact, and fluid
transfer during recrystallization and alteration.