Station One - Gneiss
MY TEACHERS ARE VERY GNEISS
(Write this description on your lab sheet)
This metamorphic specimen used to be the igneous rock Granite. Pressure
has forced the Mica and Quartz into layers. A metamorphic rock with layered
textures is called a foliated metamorphic rock.
1. Is this a foliated or non-foliated rock? Explain your answer.
2. What are two minerals often found in gneiss?
Station Two - Schist
Aahh Schist!
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This metamorphic rock is called Schist and is formed from Graphite. The
layers in this rock are parallel and should be solid grey in color unless
impurities exist.
1. Compare the texture of the Schist to the Graphite (graphite is the shiny
one).
2. Is this a foliated or non-foliated rock? Explain your answer.
Station Three – Pyroxene Hornsfel
Pyroxene Hornsfel
(Write this description on your lab sheet)
This Metamorphic rock forms where the temperature is highest. This is
a fine to medium grained rock, with an even grain size composed of
Quartz, Mica, and Pyroxene.
1. Is this a foliated or non-foliated rock? Explain your answer.
2. What are two minerals often found in Hornsfel?
Station Four - Slate
Slate
(Write this description on your lab sheet)
Slate is a metamorphic rock made from the sedimentary rock Shale. Slate is
formed from sediments like Clay, Mudstones and Shale (you have a piece of
Shale in the bucket). Slate has a very fine texture and splits very cleanly along
its rock planes. (Math hint: a plane is any flat surface).
1. Is this a foliated or non-foliated rock? Explain your answer.
2. Compare the texture of the two samples. Do you think Shale would
break cleanly into layers like Slate? Explain your thinking.
Station Five - Phyllite
Phyllite (Fi-light)
(Write this description on your lab sheet)
This metamorphic rock is like both Schist and Slate. Mica and chlorite are
essential components and give it its sheen and color. Yes, it is an example
of a foliated rock.
1. Why would Phyllite be considered a foliated rock? Explain your
reasoning...
2. Rub the sample with your thumb (kind of hard). Does it leave a residue
(mark)? Describe the residue.
Station Six – Soapstone
Soapstone
(Write this description on your lab sheet)
This is a rock usually very rich in Talc. It has a soapy feel, which is where its
name comes from. This is a soft rock and can be used for carvings. You also
have a sample of the mineral Talc.
1. Study the specimen, is it foliated or non-foliated?
2. How is the Soapstone different from the Talc.
Station Seven – Quartzite
Quartzite
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Quartzite are metamorphosed sandstones which have been recrystallized so that in breaking, they break through the quartz grains
instead of through the cement as in sandstones. Quartzite like marble in
a “massive” metamorphic rock, which means it’s very hard and tough.
1.
Is this a foliated or non-foliated rock? Explain your answer.
Station Eight – Marble
Have You Lost Your Marble?-is re-crystallized Limestone.
(Write this description on your lab sheet)
Marble is a re-crystallized metamorphic form of Limestone. Marble is
composed essentially of Calcite. The fossils, which would have been in
the Limestone are lost during metamorphic re-crystallization.
1. If marble is re-crystallized, was there pressure and/or heat involved in
the change? Explain your thinking...