Rock Identification Lab

Let's start with the vesicular texture:Locate your 2 rocks with holes in them.

Pumice has holes and light coloring (felsic).

Pumice is rock number...

• 1

• 3

• 6

• 7

Now let's look at the other vesicular rock (holes).

Scoria is dark colored and has many holes from rapid cooling at the surface.

Scoria is rock number...

• 3

• 1

• 6

• 7

Which rock is obsidian? It is also known as volcanic glass.

• 1

• 3

• 8

• 9

Let's focus on intrusive (large crystals). There should be 3 rocks that have large crystals. What are the 3 with large crystals

• 1,2, 4

• 1,4,5

• 1,8,3

• 2, 3,8

The intrusive rock (from the last question) that is lightest in color (or contains light pink) is granite. Which rock number is granite?

• 1

• 2

• 4

• 5

The intrusive rock (from question 4) that is darkest in color is gabbro. Which rock number is gabbro?

• 1
• 2
• 4
• 5

The intrusive igneous rock (from question 4) that is half light and half dark (polka dots) is diorite. Which mineral is diorite?

• 1

• 2

• 4

• 5

Now you can pull out the 3 rocks you have left to identify. They should be.....

• 2, 3, 8

• ----

• -----

• -----

The darkest of the extrusive is basalt. Which number is basalt?

• 2

• 3

• 8

• ---

The remaining rock should be porphorytic (both small and big crystals). It should be the intermediate extrusive rock andesite. Which number is andesite?

• 2

• 3

• 8

• ---