Geoscience Exam 1

What is the definition of a mineral?

A naturally occurring, inorganic solid with an ordered internal structure and definite chemical composition

Which tests can be used to differentiate gold and pyrite?

Both

Which mineral has a metallic luster?

Galena

Which mineral does not have cleavage?

Quartz

Which mineral has only one plane of cleavage?

Muscovite

Which mineral is harder than a glass plate (5.5)?

Quartz

Which mineral effervesces when in contact with HCI?

Calcite

Which rock has the same mineral composition as andesite?

Diorite

A felsic rock has ______ silica and melts at a ______ temperature than a mafic rock.

More, lower

Which rock cooled quickly above ground?

Rhyolite

Which rock is mafic and intrusive?

Pegmatite

Which rock has very large crystals?

Pegmatite

Which of the following rocks can be described as chemical?

Limestone

What is the dominant grain size of shale?

Clay

What is the difference between a breccia and a conglomerate?

Different grain shapes

Shale can be described as _______.

Fissile

Coal forms in a(n) _______.

Swamp

Metamorphic rocks are formed from _______ and _______.

Heat, pressure

What type of metamorphism occurs near mountain ranges formed from tectonic plate subduction?

Regional

Which of the following is a metamorphic, foliated rock?

Schist

Which of the following is the correct order of metamorphic rocks of increasing metamorphic grade?

Slate -> Phyllite -> Schist -> Gneiss

Pyrite identifiers

Brassy to golden yellow, luster is bright and metallic, conchoidal fracture, no cleavage, greenish streak

Galena identifiers

Gray to silver, metallic luster when fresh, three planes of cleavage resulting in perfect cubes, dark gray streak

Quartz identifiers

Clear to mulitcolored, vitreous (glassy) luster, curved conchoidal fracture, white streak

Amphibole identifiers

Non-metallic, typically vitreous in luster, elongated black prism, at most two cleavage planes

Fluorite idenitfiers

Typically green or purple, easily scratched, vitreous luster, has cleavage

What is the difference between Biotite mica and Muscovite mica?

Biotite is dark and Muscovite is light

Calcite Identifiers

Can be scratched by a fingernail, vitreous luster, double refraction

Sulfer identifiers

Bright yellow, stinky, very soft, yellow streak

Gypsum identifiers

One plane of cleavage, easily scratched by a fingernail, does not effervesce like calcite

Talc identifiers

Greasy or soapy feel, can be scratched with a fingernail, luster is pearly