Properties of Minerals
Introduction:
All natural earth materials are made up of minerals. Some rocks are made of only
one mineral but most rocks are made of a mixture of several minerals. There are over
2000 known minerals, but only about a dozen referred to as “common rock-forming
minerals” which make up most of the earth’s crust. Before you can identify rocks, you
must be able to recognize the minerals found in the rocks.
What is a mineral? By definition, I mineral must be inorganic. Inorganic means
a substance that is not alive and was never part of something alive. Minerals must also be
natural. They were never “man-made”. A mineral is homogeneous, which means it is
the same material throughout. It is not made of different materials in different parts of
the specimen. Minerals are made of elements or compounds that have a definite
composition. And finally, minerals have the same physical properties throughout the
sample.
In this lab investigation, you will identify mineral samples by makin observations
and testing the physical properties.
Objectives: after you have completed this lab investigation you should be able to:
1. Identify mineral samples by making observations and testing physical properties.
2. Use a mineral identification key.
Materials:
Mineral Samples
Glass Plate
Streak Plate
Mineral Identification Key
Procedure:
1. You may do the minerals samples in any order.
2. Work with only ONE mineral sample at a time and return it to the proper
container before selecting another sample.
3. Carefully test and observe each mineral sample to determine its physical
characteristics. Record your observations on the Report Sheet.
4. Use the Mineral Identification Key and your Earth Science Reference Tables to
identify the mineral and record the name of the mineral in the last column on the
Report Sheet.
5. Before selecting another sample, bring it up to the teacher and tell him what you
think the mineral is.