Essentials of Geology (Geol 1030)
Laboratory #2-Minerals
Introduction
Welcome to the quintessential physical geology laboratory! This begins a four session
laboratory in observing, describing, classifying, and learning the Earth’s physical products.
Minerals are the basic materials in geology, most rocks & some fossils are made up of minerals.
If you work during this laboratory you will be able to identify the common rock-forming minerals
for the rest of your life. If you chat with your neighbor and then just try to memorize the
minerals, you will not perform well on the identification exam. That’s right, you will identifying
the minerals and the rocks that are made up of minerals on an exam. There are about 3,500
known minerals and you are responsible for learning the minerals that make up 99% of the
Earth’s crust (page 62 in your textbook explains). Fortunate for you, that is just a handful of
minerals (you are responsible for knowing twelve minerals on the test).
First & Foremost
What is a mineral? If you do not know the five properties required to be a mineral, you
better learn it now and please do not tell your instructor you don’t know. He may have a heart
attack! List the 5 characteristics below:
1. 2.
3. 4.
5.
Is it a mineral, yes or no? Refer to your list above to make sure.
A snowflake____________ coal______________
Table salt ______________ window glass _____________
Petroleum______________ volcanic glass______
How to identify minerals
There are several physical properties of minerals that will be diagnostic in determining
minerals. Learn the process and then select a few of the most important properties that set each
mineral apart from the others. Read pages 68-70 in your text before this lab! You instructor will
walk you through the process on the first mineral. The dichotomous key below is crucial to
learning the minerals, but keep in mind you will not be able to use it on the exam! Consequently,
complete the table at the end of this lab, then circle or highlight the properties that distinguish that
mineral from the others samples that are most like it. The first step in the identification is to
separate the minerals by luster into metallic or non-metallic. Practice with these! Appendix C in
your book may be used as a reference. Here are the ones you are responsible for:
THE DIRTY DOZEN
Orthoclase Plagioclase Quartz Muscovite
Augite Hornblende Biotite Olivine
Calcite Gypsum Galena Magnetite
