rocks, minerals, rock cycle

Comprehensive vocabulary flashcards covering the Earth's interior layers, mineral properties, weathering, erosion, sedimentary, igneous, and metamorphic rock formation, the rock cycle, volcanoes, and mining processes.

Crust

The thin, outermost layer of the Earth consisting mostly of oxygen and silicon, compared with the Earth's radius of about $6370\,km$.

Oceanic Crust

The thinner part of the Earth's crust that measures between $5\text{ to }10\,km$ in thickness.

Continental Crust

The thicker part of the Earth's crust that measures between $30\text{ to }70\,km$ in thickness.

Mantle

The layer of the Earth located directly beneath the crust, containing the asthenosphere which moves via convection currents.

Outer Core

The liquid layer of the Earth's core, composed primarily of iron and nickel.

Inner Core

The solid, innermost, and hottest layer of the Earth, composed primarily of iron and nickel.

Mineral

A naturally formed, inorganic substance with a definite chemical makeup and a crystalline structure.

Ore

A rock containing valuable minerals or metals (such as iron, gold, or copper) that can be extracted and mined for profit.

Mohs Scale

A scale ranging from 1 to 10 used to measure mineral hardness based on resistance to being scratched.

Streak

The colour of the powder left behind when a mineral is scraped across an unglazed porcelain tile.

Lustre

A physical property describing how shiny a mineral is and how it reflects light.

Weathering

The process that breaks down rock into smaller pieces in the same place without moving them.

Freeze-Thaw Weathering

A form of physical weathering where water seeps into rock cracks, freezes and expands by about $9\%$, and widens the crack to eventually split the rock.

Chemical Weathering

The breakdown of rocks via chemical changes, such as oxidation rusting iron or acid rain dissolving limestone and marble.

Biological Weathering

The breakdown of rocks caused by living organisms, such as tree roots, lichens, and burrowing animals.

Erosion

The process that moves weathered rock fragments (sediment) to a new location via moving water, wind, ice (glaciers), or gravity.

Deposition

The settling of transported sediment when water, wind, or ice slows down, causing heavier particles to drop first and finer particles to drop last.

Compaction

The process where layers of sediment are compressed and squeezed together by the weight of overlying layers.

Cementation

The process where dissolved minerals precipitate and glue sediment grains together to create solid rock.

Friable

A crumbly texture typical of certain sedimentary rocks.

Clastic Sedimentary Rock

Sedimentary rock made from pre-existing rock fragments that were deposited, compacted, and cemented together, such as sandstone, conglomerate, and shale.

Chemical Sedimentary Rock

Sedimentary rock formed when dissolved minerals crystallize or precipitate out of solution, such as rock salt (halite) and certain types of limestone.

Biological Sedimentary Rock

Sedimentary rock formed from the accumulated remains of once-living organisms, such as coal and certain types of limestone.

Fossil

The preserved remains or traces of organisms that lived in the past, most commonly discovered in sedimentary rock.

Magma

Molten rock situated underneath the surface of the Earth.

Lava

Molten rock that has erupted onto or reached the surface of the Earth.

Igneous Rock

A rock category formed through the cooling and solidification of molten rock (magma or lava).

Intrusive Igneous Rock

Igneous rock formed from magma that cools slowly deep underground, resulting in large, visible crystals (e.g., granite and diorite).

Extrusive Igneous Rock

Igneous rock formed from lava cooling rapidly at or above the surface, forming small crystals, a glassy texture, or trapped gas holes (e.g., basalt, obsidian, pumice, and scoria).

Metamorphic Rock

Rock formed when existing rock is altered by intense heat and/or pressure deep underground without fully melting.

Foliation

The texture in metamorphic rocks where mineral grains are flattened and aligned into parallel bands or layers under pressure.

Parent Rock

The original pre-existing rock that undergoes transformation through heat and pressure to become a metamorphic rock.

Rock Cycle

A continuous geological model demonstrating how rocks form, break down, and change between igneous, sedimentary, and metamorphic forms over time.

Magma Chamber

An underground cavity or reservoir beneath a volcano where magma accumulates.

Volcanic Vent

A central or side conduit through which magma, ash, and gases escape to the surface during a volcanic eruption.

Volcanic Crater

A bowl-shaped hollow or depression at the summit of a volcano surrounding the central vent.

Diamond

A crystalline mineral form of pure carbon that crystallizes under intense heat and pressure at extreme depths in the Earth.

Flame Test

A diagnostic procedure where a mineral is placed into a hot flame to observe the characteristic colour emitted.

Bauxite

An aluminium ore mined extensively in Western Australia.

Rehabilitation

The final stage in mineral recovery that restores, replants, and repairs the mined land for the community and environment.

Geology

The scientific study of the Earth, its rocks, minerals, and the physical processes that shape its structure.

Crust

The outermost, thinnest layer of the Earth, composed primarily of oxygen and silicon, with oceanic crust measuring $5\text{ to }10\,\text{km}$ and continental crust measuring $30\text{ to }70\,\text{km}$.

Mantle

The Earth layer located beneath the crust containing the asthenosphere, which flows via convection currents and serves as the source of magma.

Outer Core

The liquid layer of the Earth situated between the mantle and inner core, composed predominantly of iron and nickel.

Inner Core

The hottest, innermost solid layer of the Earth, composed mostly of iron and nickel, remaining solid due to immense pressure despite extreme temperatures.

Mineral

A naturally occurring, inorganic substance with a definite chemical composition and crystalline structure, which forms the building blocks of rocks.

Rock

A solid mass composed of one or more naturally occurring minerals or mineral-like substances.

Ore

A naturally occurring rock that contains sufficient valuable minerals or metals (such as iron, gold, copper, lithium, or bauxite) to be mined for profit.

Streak

The colour of a mineral in its powdered form, determined by rubbing the mineral across an unglazed porcelain streak plate.

Lustre

The physical property that describes how shiny a mineral is and the way light reflects off its surface.

Mohs Scale

A relative hardness scale ranging from $1\text{ to }10$ used to identify minerals by determining their resistance to scratching.

Flame Test

A diagnostic test used to identify certain minerals by observing the distinct colour produced when a sample is placed in a hot flame.

Weathering

The mechanical, chemical, or biological process of breaking down rock into smaller fragments in the same place without moving it.

Freeze-Thaw Weathering

A type of physical weathering where water seeps into a crack in a rock, freezes, expands by approximately $9\%$, and wedges the crack wider through repeated cycles until the rock splits.

Chemical Weathering

The breakdown of rocks via chemical alteration of their minerals, such as iron oxidation rusting rock (giving Uluru its red colour) or acid rain dissolving limestone and marble.

Biological Weathering

The breakdown of rock caused by living organisms, such as tree roots prying fractures apart, lichens releasing acids, or burrowing animals.

Erosion

The transportation of weathered sediment from one location to another by agents such as moving water, wind, ice (glaciers), or gravity.

Deposition

The settling or dropping of weathered sediment when transporting agents (water, wind, or ice) lose energy and slow down, with heavier particles settling first.

Compaction

The sedimentary process where accumulating layers of sand, silt, clay, and mud are squeezed tightly together by the weight of the overlying sediment.

Cementation

The sedimentary process where dissolved minerals precipitate out of water and glue individual sediment grains firmly together.

Friable

A physical texture characteristic of certain sedimentary rocks indicating that they are easily crumbled or broken apart into grains.

Clastic Sedimentary Rock

A category of sedimentary rock formed from accumulated, compacted, and cemented fragments of preexisting rocks, such as sandstone, conglomerate, and shale.

Chemical Sedimentary Rock

Sedimentary rock that forms when dissolved minerals precipitate out of an evaporating or saturated solution, such as rock salt (halite) and certain types of limestone.

Biological Sedimentary Rock

Sedimentary rock formed from the compacted and cemented organic remains of plants or animals, including coal and some limestones.

Fossil

The preserved remains, impressions, or evidence of ancient organisms, found almost exclusively in sedimentary rock because the heat and pressure of other rock formations destroy organic matter.

Igneous Rock

Rock formed by the cooling and solidification of molten rock (magma beneath the ground or lava on the surface), featuring interlocking crystals, glassy textures, or vesicles.

Magma

Molten rock located beneath the Earth's surface within the crust or mantle.

Lava

Molten rock that has broken through the Earth's crust and erupted onto the surface.

Intrusive Igneous Rock

Igneous rock formed from magma that cools slowly deep underground, allowing large, visible, interlocking mineral crystals to grow, such as granite and diorite.

Extrusive Igneous Rock

Igneous rock formed from lava cooling rapidly on or above the Earth's surface, resulting in fine-grained crystals, a glassy texture, or trapped gas holes, such as basalt, obsidian, pumice, and scoria.

Pumice

A lightweight extrusive igneous rock filled with gas bubbles trapped during rapid cooling, giving it a low enough density to float on water.

Metamorphic Rock

Rock that has been physically and chemically transformed from an existing rock by intense underground heat and/or pressure without actually melting.

Foliation

The parallel alignment of platy or elongated mineral grains into visible layers or alternating bands caused by directional pressure during metamorphism.

Parent Rock

The original rock that undergoes alteration by intense heat and pressure to become a metamorphic rock (e.g., shale becoming slate, limestone becoming marble, or sandstone becoming quartzite).

Rock Cycle

A dynamic geological model showing how rocks continuously transform between igneous, sedimentary, and metamorphic types via processes such as melting, cooling, weathering, erosion, compaction, cementation, heat, and pressure.

Magma Chamber

A large pool or reservoir of liquid molten rock located beneath a volcano.

Crater

A circular, bowl-shaped depression at the top or summit of a volcano surrounding the main central vent.

Diamond

A mineral composed of pure crystallized carbon formed under intense heat and pressure deep within the Earth's mantle, extracted using open-cut or underground mining.

Bauxite

A commercially valuable ore mined extensively in Western Australia that serves as the principal raw source of aluminium.

Rehabilitation

The final phase of the mineral extraction process where mined land is repaired, replanted, and returned to a stable, natural, or productive state for the community and environment.