IGNEOUS ROCK IDENTIFICATION LAB
Name:
Date:
Objective
To practice identifying igneous rocks based on color, mineral composition, and texture
Materials
•
Igneous Rock Identification Table (in the lesson)
•
8 Igneous Rock Samples (Images in lesson)
Procedure
1.
Complete the
Purpose
and
Hypothesis
sections of your lab worksheet.
2.
Complete the data table for each rock sample by identifying the characteristics of the rock
samples using the images in Canvas and the Igneous Rock Identification Table provided. See
Steps 3–5 for how to utilize the Igneous Rock Identification Table.
3.
Observe the color of the rock sample. If the color is dark, it is considered
mafic,
and you will look
on the mafic column to determine the possibilities that it could be. If the color is light, it is
considered
felsic
. If it is in between, look at the intermediate column.
NOTE: Obsidian is covers all three columns because it is mostly made of quartz with a small
number of dark minerals. Reddish colored rocks are considered dark.
4.
Decide whether it is intrusive or extrusive (volcanic). Ask yourself, “Am I able to see the
interlocking
crystals in this rock?” If the answer is “No,” you will want to follow the extrusive
(volcanic) row across. Also, determine other characteristics of the rock's texture. For example, if
it contains holes, it is considered
vesicular
.
5.
You will find the rock name where the color column and the texture row come together on the
Igneous Rock Identification Table.
6.
Complete the Data Table 1 and answer the questions that follow. Save your work, and submit
the completed lab worksheet in Canvas.
Purpose (5 pts)
Write a 1-2 sentence purpose statement for this lab. What questions are you trying to answer? What do
you hope the outcome will be?
