Lab 2

• What is the name of this rock?

  Diorite

  
• Name the rock

  Gabbro

  
• Name the rock

  andesite

  
• Which rock is shown?

  scoria

  
• Name the rock

  Llanite

  
• Name the rock

  obsidian

  
• Name the rock

  granite

  
• Name the rock

  pumice

  
• What is this rock?

  rhyolite

  
• Which metamorphic is shown below?

  rhyolitic tuff

  
• Which rock is this?

  welded tuff

  
• Which rock is this?

  basalt

  
• What is the name of this rock?

  basalt porphyry

  
• Which metamorphic rock is this?

  Granite pegmatite

  
• What is the name of this rock?

  Peridotite

  
• What is diorite’s composition and texture?

  Intermediate: Diorite is composed mainly of amphibole and albite

  Texture: Diorite has a coarse-grained texture (Phaneritic).
• What is the cooling rate for diorite?

  Slow and therefore, it is an intrusive rock.
• What is gabbro’s composition and texture?

  Composition: mafic

  Texture: phaneritic
• Gabbro has a slow cooling rate and therefore an intrusive or plutonic rock.
• Adesite has an intermediate composition and a porphyritic texture.

  The cooling rate is non-uniform and therefore both an intrusive and extrusive rock.
• All porphyritic-textured rocks have a non-uniform cooling rate and are always both extrusive and intrusive rock.
• What is scoria’s texture?

  Vesicular
• Scoria is a mafic rock with rapid cooling rate (extrusive).
• Llanite is a felsic rock with a porphyritic texture.
• What is Llanite’s cooling rate?

  Non-uniform.
• TRUE OR FALSE: Obsidian rock has a felsic composition.

  True
• Obsidian is a a felsic rock that cooled fast (extrusive) and has a glassy texture.
• Granite is a felsic rock that has a phaneritic texture. It cooled slowly, therefor intrusive.
• Pumice is an intrusive rock that is vesicular and has a felsic composition.
• Pumice cooled down slowly.
• Rhyolite is a felsic rock with aphanitic texture.
• Rhyolite is an extrusive rock.
• What is the composition of a rhyolitic tuff?

  Felsic
• Rhyolitic tuff is a pyroclastic rock that cooled fast.
• Rhyolitic tuff is also called a non-welded tuff.
• Welded tuff is pyroclastic, cooled fast, and has a felsic composition.
• Basalt is a mafic rock that has an aphanitic texture.
• Basalt cooled fast, therefore an extrusive rock.
• Basalt porphyry is a mafic rock that has a porphyritic texture.
• Basalt porphyry has a non-uniform cooling rate.