GEOL-1403
Igneous Rock Identification
Review the literature on the following page regarding igneous rock classification. On the pages that follow, you
will find an image of a rock and an Igneous Rock Identification Chart. Identify the composition by identifying the
color and determine the texture by examining the crystal sizes that are present. Once this is done the rock
name is easily determined using the Classification of Igneous Rock chart. Click each answer, then check to see
if you have correctly identified the rock sample. Complete and submit the table below for grading.
Sample
number
Composition
Texture
Name of rock
1
Mafic
Aphanitic
Basalt
2
Intermediate
Phaneritic
Diorite
3
Ultramafic
Phaneritic
Dunite
4
Mafic
Phaneritic
Gabbro
5
Felsic
Phaneritic
Granite
6
Felsic
Phaneritic
Granite
7
Felsic
Glassy
Obsidian
8
Felsic
Vesicular
Pumice
9
Felsic
Porphyritic
Rhyolite
10
Mafic
Vesicular
Scoria
11
Intermediate
Porphyritic
Andesite
12
Felsic
Pyroclastic
Volcanic Tuf
