Geo 101 Chpt 3

Which of the following is a mineral?

• petroleum (oil), which is a liquid

• cubic zirconia, which is a synthetic diamond substitute that is not found in nature

• coal, which was formed from ancient tropical plants

• ice, which is water in the solid state (and water is essential to all organic life on Earth)

Two distinct minerals may have the same chemical formula.

• True

• False

A single mineral may take on multiple crystalline lattice structures.

• True

• False

Natural glass is not considered a mineral because it .

• is not produced by geologic processes

• is organic

• does not have fixed crystalline structure

• can be made synthetically as well as being a naturally occurring substance

Minerals in geodes form spectacular euhedral crystals because .

• all of the elements incorporated in the crystals are in plentiful supply

• the crystals have abundant room to grow in their hollow surroundings

• minerals within geodes are always framework silicates

• minerals within geodes always contain iron

Diamond and graphite are both polymorphs of pure silicon.

• True

• False

The most useful diagnostic property of minerals is their color in hand sample.

• True

• False

For the majority of minerals, the streak color obtained when the mineral is scratched against a porcelain plate is .

• likely to be diagnostic only if the mineral is hard enough to scratch porcelain

• more variable than the color in hand sample among crystals

• less variable than the color hand sample among crystals

• always dark brown or black

The shininess of a mineral is a helpful diagnostic property termed .

• color

• specific gravity

• luster

• streak

Cleavage in minerals refers to .

• a tendency to break in an irregular pattern

• a tendency to break along planes of weakness

• the sharpness of edges between crystal faces

• the development of distinct crystal faces