E.S. Chapter 3: Minerals and Rock Classification

Vocabulary flashcards focusing on mineral properties, chemical bonding, silicate structures, and rock classifications from Chapter 3.

Mineralogy

The study of minerals.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure.

Crystalline Structure

An orderly arrangement of atoms inside a crystal that produces distinct crystal forms.

Streak

The color of the powdered form of a mineral, produced by rubbing the mineral against an unglazed porcelain streak plate.

Luster

The way a mineral's surface reflects light, classified as metallic or nonmetallic (such as glassy, silky, satiny, resinous, pearly, or earthy).

Hardness

A measure of the ability of a mineral to resist scratching, measured on the relative Mohs scale.

Crystal Habit

The shape of a single, well-formed crystal or the character of an aggregate of many well-formed crystals that grew together as a group.

Cleavage

The property of a mineral breaking along distinctive planar surfaces corresponding to weak internal bonding planes.

Fracture

The tendency of a mineral to break along non-regular planar surfaces due to internal bonds of equal strength in all directions.

Octet Rule

A rule of chemical bonding stating that atoms gain, lose, or share electrons until surrounded by eight valence electrons.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Ionic Bonding

Chemical bonding that occurs when an atom gains or loses valence electrons.

Covalent Bonding

Chemical bonding that occurs when a pair of atoms share one or more valence electrons.

Silicates

The most abundant group of minerals on Earth, constituting 90% or more of rocks, formed by silicon-oxygen tetrahedra.

Silicon-Oxygen Tetrahedron

The basic building block of silicates, consisting of a silicon atom at the center surrounded by four oxygen atoms ($\text{SiO}_4^{4-}$).

Rock

A coherent, naturally occurring solid mass consisting of an aggregate of mineral grains or mineral-like materials.

Bedrock

Rock at the surface of the Earth that remains attached to the Earth's crust below.

Outcrop

A surface exposure of bedrock.

Genetic Classification

A system developed in the 18th century that classifies rocks based on their origins into igneous, sedimentary, and metamorphic types.

Igneous Rock

Rock formed when molten rock (magma or lava) solidifies at or below Earth's surface.

Sedimentary Rock

Rock formed at or near Earth's surface when mineral grains are cemented together or when mineral crystals precipitate.

Metamorphic Rock

Rock formed when preexisting rocks undergo physical and chemical changes in response to heat and pressure without melting.

Rock Cycle

A geological concept illustrating the various pathways rock material takes as it undergoes processes in Earth's crust.