Igneous Rock Identification

1
Igneous Rock Identification
2
ESRT Page 6 Igneous Rock Scheme
Click on the Rock Name for Pictures and More Info
Obsidian
Vesicular Andesite
Pumice
Scoria
Rhyolite
Basalt
Andesite
Granite
Gabbro
Diorite
Pegmatite
3
Obsidian

• Non-Vesicular Glassy Texture
• Felsic Composition
• Usually Black may be Brown
• Extrusive

4
Pumice

• Vesicular Glassy Texture
• Felsic Composition
• Very Light Weight
• Extrusive

5
Rhyolite

• Non-Vesicular Fine Texture
• Felsic Composition
• Very Light Weight Pinks, White, Clear and Black
• Extrusive

6
Vesicular Andesite

• Vesicular Fine Texture
• Intermediate Composition
• Gray, Tan, Brown
• Extrusive

7
Scoria

• Vesicular Fine Texture
• Intermediate Composition
• Dark Brown, Grey
• Extrusive

8
Andesite

• Non-Vesicular Fine Texture
• Intermediate Composition
• Grays to Brown
• Extrusive

9
Basalt

• Non-Vesicular Fine Texture
• Mafic Composition
• Blacks to Greens
• Extrusive

Vesicular Basalt
10
Granite

• Non-Vesicular Coarse Grained Texture
• Felsic Composition
• Pinks, White, Clear and Black
• Intrusive

11
Diorite

• Non-Vesicular Coarse Grained Texture
• Intermediate Composition
• White, Clear, Gray and Black
• Intrusive

12
Gabbro

• Non-Vesicular Coarse Grained Texture
• Mafic Composition
• White, Gray, Black and Greens
• Intrusive

13
Pegmatite

• Non-Vesicular Very Coarse Grained Texture
• Felsic Composition
• Pinks, White, Clear and Black
• Intrusive