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Lab Setup

1. RHYOLITE

• Texture: Aphanitic/ fine grained• Crystal size: small• Composition: Felsic/ K feldspar,

quartz, plagioclase feldspar…• Color: light/ pink-grey• Extrusive

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2. GRANITE

• Phaneritic/ course grained• Felsic

3. PEGMATITE

• Ultra course/ Phaneritic• Felsic

• Like granite but BIGGER crystals

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4. BASALT

• Aphanitic/ fine grained• mafic

5. DIORITE

• Phaneritic/ course grained• Intermediate

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6. PUMICE

• Frothy Glass• Felsic

7. SCORIA

• Frothy Glass• Mafic

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8. OBSIDIAN

• Glassy• Felsic

• BE CAREFUL! THIS IS THEEXCEPTION TO THECOLOR RULE!