earth science ch. 3

Minerals are all naturally occurring solid substances with a definable chemical composition. They must also possess

a fixed crystalline structure (spatial arrangement of atoms and ions).

Cleavage in minerals refers to

a tendency to break along planes of weakness.

Which of the following minerals is more commonly known as table salt?

halite

What type of rock forms by the solidification of a melt?

igneous

Diamonds are usually found in

kimberlite.

Which of the following forms either by the cementing together of grains broken off preexisting rocks or by the precipitation of mineral crystals out of water solutions at or near the Earth's surface?

sedimentary rocks

The mineral class that makes up more than 95% of rocks in the continental crust is termed the

silicates.

Which of the following is a mineral?

snowflakes

A mineral property defined by the density of the mineral sample divided by the density of water (1.0 g/cm3) is

specific gravity.

The color of a mineral in powdered form is termed

streak.

Pyrite (FeS2) is in which mineral class?

sulfides

Which of the following common minerals is softest?

talc

Which of the following is NOT true about minerals?

All minerals are compounds of more than one element.

With regard to minerals, hardness refers to the ability to resist

being scratched

Which of the following is NOT a way for minerals to crystallize?

bonding carbon to oxygen atoms to form organic compounds

The image below shows a mineral with hydrochloric acid applied to it. What mineral is this?

calcite

Which of the following is a mineral?

calcite

Calcite (CaCO3) is in which mineral class?

carbonates

Trace amounts of impurity in a mineral can commonly produce significant differences in __________ among individual crystals of this mineral.

color

The image below shows a mineral specimen of quartz. What is the term for the smoothly curving, clamshell-shaped surface on the sample below?

conchoidal fracture

Synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed

conchoidal fracture.

The diamonds typically seen in engagement rings today do not display their natural crystal faces but rather __________, which are made by grinding the gem on a spinning lap.

facets

A __________ is a mineral-lined cavity in a rock.

geode

Ore minerals, such as galena, tend to be different from typical minerals (such as quartz) in that they have a

large specific gravity.

What type of rock forms when preexisting rocks undergo changes in response to a modification of their environment, without first melting?

metamorphic rocks

Which of the following minerals is a silicate?

olivine

For most minerals, the streak color obtained when the mineral is scratched against a porcelain plate is

only useful if the mineral is softer than porcelain.

Geologists refer to an exposure of bedrock on the surface as a(n)

outcrop

Which layer of Earth does NOT contain silicate minerals?

outer core

The tetrahedral structure that forms the backbone of all silicate minerals is composed of silicon and what other element?

oxygen

Which of the following is NOT a mineral?

petroleum

A facet is a __________ on a gem.

polished surface

When a solution becomes oversaturated, new solid particles are said to

precipitate from the solution.

Minerals that grow around volcanic vents MOST likely form by

precipitation from a gas.