Mineral Groups and Their Characteristics

Mineral

Naturally occurring inorganic solid with a defined composition.

Organic vs inorganic

Organic contains carbon; inorganic does not.

Gem

Precious or semi-precious stone, often cut and polished.

Luster

Appearance of light reflected from a mineral's surface.

Streak

Color of a mineral's powder when scraped.

Opaque

Material that does not allow light to pass through.

Translucent

Material that allows some light to pass through.

Transparent

Material that allows light to pass through clearly.

Crystal habit

External shape of a crystal as it grows.

Mohs hardness scale

Scale from 1 to 10 measuring mineral hardness.

Tenacity

Resistance of a mineral to breaking or deforming.

Fracture

Irregular breakage of a mineral without cleavage.

Conchoidal fracture

Smooth, curved surfaces resembling a shell.

Cleavage

Tendency of a mineral to break along flat planes.

Specific gravity

Ratio of a mineral's density to water's density.

Silicates

Most common mineral group, containing silicon and oxygen.

Silicon-oxygen tetrahedron

Fundamental building block of silicate minerals.

Light silicates

Minerals lighter in color and less dense.

Feldspar

Most common mineral in Earth's crust, contains K.

Quartz

Second most common silicate, made of Si and O.

Muscovite

Mica with one-directional cleavage, used in cosmetics.

Dark silicates

Minerals darker and denser than light silicates.

Olivine Group

High-temperature silicates, black to olive green.

Pyroxene Group

Diverse minerals in dark igneous rocks, e.g., augite.

Amphibole Group

Includes hornblende, forms elongated crystals.

Biotite

Iron-rich mica with excellent one-directional cleavage.

Non-silicate minerals

Grouped by anion present or single elements.

Non-renewable resources

Resources formed slowly, taking millions of years.

Renewable resources

Resources replenished over relatively short time spans.