Rocks & Minerals Review

Flashcards covering key terms and concepts related to rocks and minerals, including definitions and properties.

Luster

The way light interacts with the surface of a mineral, can be metallic or non-metallic.

Cleavage

The tendency of a mineral to break along flat planes of weakness.

Fracture

The way a mineral breaks when it does not cleave.

Hardness

A measure of a mineral's resistance to scratching, rated on the Mohs scale.

Streak

The color of the powder produced when a mineral is scraped across a porcelain plate.

Amphibole (Hornblende)

A mineral that is black with a splintery, glassy luster and exhibits 2 cleavage planes at 120°.

Biotite Mica

A black mineral known for its thin, planar cleavage and non-metallic luster.

Calcite

A mineral characterized by its rhombohedral cleavage, hardness of approximately 3, and reaction with hydrochloric acid.

Corundum

A very hard mineral with a hardness of 9, known for its hexagonal prism habit.

Dolomite

A mineral that exhibits rhombohedral habit and cleavage, and reacts with acid when powdered.

Galena

A dense silver-gray mineral with cubic cleavage and a hardness of 2.5-3.5.

Garnet

A mineral with a dodecahedral growth shape and no cleavage.

Graphite

A very soft mineral that can write on paper and has a black streak.

Gypsum

A soft mineral that can be easily scratched with a fingernail and exhibits one main cleavage plane.

Halite

A mineral known for its salty taste and cubic cleavage.

Hematite

A mineral that may have a red or reddish-brown streak and may weakly attract magnets.

Kyanite

A mineral that exhibits a bladed habit and has a hardness of 5.5-7.

Magnetite

A mineral that attracts magnets and has a dark grey-black streak.

Muscovite

A transparent mineral characterized by thin, planar cleavage.

Olivine

A translucent mineral that is typically green or black, with a glassy appearance.

Plagioclase Feldspar

A mineral that displays two cleavage planes at 90° and may have striations.

Potassium Feldspar (Orthoclase)

A mineral with 2 cleavage planes at 90°, often pink, and may have lamellae.

Pyrite

A metallic mineral often called 'Fool's Gold,' known for its cubic crustal growth.

Quartz

A common mineral that has a hardness of 7, known for conchoidal fracture and scratches glass.

Sulfur

A yellow mineral that has a distinctive rotten egg smell.

Talc

A very soft mineral that feels soapy and powdery.

Andesite

An igneous rock with an aphanitic texture that has an intermediate composition.

Basalt

An igneous rock that is aphanitic and possibly vesicular, with a mafic composition.

Diorite

An igneous rock with a phaneritic texture and intermediate composition, often having dalmatian spots.

Granite

A phaneritic igneous rock that can be pink but not all granite is characterized by color.

Obsidian

A glassy igneous rock that displays a conchoidal fracture.

Pumice

A light-weight igneous rock known for its vesicular texture.

Rhyolite

An aphanitic igneous rock with a felsic composition.

Scoria

A vesicular igneous rock that has an intermediate composition.

Breccia

A clastic sedimentary rock composed of big, angular clasts.

Chalk

A biological sedimentary rock that is white, powdery, and reacts with acid.

Coquina

A type of biological sedimentary rock composed of loosely cemented fossil crumbs.

Quartz Sandstone

A clastic sedimentary rock characterized by visible, translucent quartz grains.

Slate

A metamorphic rock that breaks into flat, smooth surfaces and represents a regional metamorphic condition.

Gneiss

A foliated metamorphic rock characterized by gneissic banding.

Marble

A non-foliated metamorphic rock that is crystalline and reacts with acid.

Phyllite

A foliated metamorphic rock with a crinkled appearance.

Schist

A foliated metamorphic rock that displays glittery grains.