Geosphere, Rocks and Minerals

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lava that hardens into rough, jagged rocks with a crumbly texture

aggregate

a rock composed of a collection of small particles, minerals, or smaller pieces (like coquina)

strata

relatively flat surfaces along which sedimentary rocks tend to separate or break (layers)

Burial

A process in making sedimentary rock where a layer of sediments is buried under subsequent layers.

carbonates

A non-silicate group of minerals that contain carbon and oxygen compounds (CO3)

Cementation

A process in making sedimentary rock in which new minerals form between sediments to bind them all together.

cleavage

the tendency of a mineral to break along planes of weak bonding leaving flat surfaces. One of the physical properties of minerals useful in identification.

color

the color of a mineral sample recognized by inspection. One of the physical properties of minerals useful in identification.

Compaction

Part of the formation of sedimentary rocks. When sediments are deeply buried, the pressure of overlying layers squashes the grains together more tightly.

Compound

A combination of elements

Deposition

The geological process in which sediments, soil and rocks are added to a landform or land mass.

element

A pure substance that cannot be broken down into other substances by chemical or physical means. Symbols will be a capital letter or capital letter plus 1 lowercase letter on the periodic table of elements. Some minerals are elements.

foliation

The metamorphic rock texture in which mineral grains are arranged in planes or bands.

Fracture

When minerals break in directions other than along cleavage surfaces (i.e. not along flat planes).

Hardness

resistance of a mineral to scratching. Described on a scale from 1-10 with one being softest.

Heat &/or Pressure

Comes from magma, tectonic plate movement or deep burial. Process that creates metamorphic rocks.

igneous rock

a type of rock that forms from the cooling of molten rock at or below the surface

Inorganic

not formed from living things or the remains of living things. Was never alive.

Lava

molten (hot liquid) rock that has reached the surface

Luster

The way a mineral reflects light. Two main types are metallic and non-metallic. One of the physical properties of minerals useful in identification.

Magma

molten (hot liquid) rock located below the surface

Magma Process

As magma cools, atoms within it slow down and bond into crystalline solids/minerals. The longer it takes for the magma to cool, the larger the crystals grow.

Melting

The process of changing a rock back into magma or lava by applying heat.

Metamorphic Rock

A type of rock that forms from an existing rock that is changed by heat &/or pressure.

Mineral

a naturally occurring, inorganic, solid that possesses a definite chemical composition and structure which gives it a unique set of physical properties

Moh's Scale

a scale ranking ten minerals from softest to hardest; used in testing the hardness of minerals.

native element

A non-silicate mineral group of minerals that contain only 1 element.

Naturally-Occurring

made through non-human activity.

Naturally-occurring

Not made by humans. One of the 5 criteria of a mineral.

Oxides

A non-silicate mineral group of minerals that contain a metal and an oxygen in the compound.

Pahoehoe

A hot, fast-moving type of lava that hardens to form smooth, ropelike coils

Physical properties

Characteristics of minerals that help with identification created by the mineral's unique combination of chemical composition and arrangement of atoms.

Precipitation Process

The method of forming minerals from water with dissolved atoms/ions in it that either a) becomes supersaturated (ex: hydrothermal) OR evaporates (ex: salt flats).

Pressure Process

The mineral process where pressure and heat are applied, atoms, molecules and ions break bonds and recombine in new combinations and alignments forming new minerals.

Rock

An group of minerals bound together

Sedimentary

A type of rock that typically forms when sediment goes through the 4 part process of deposition, burial, compaction and cementation. Can also chemically precipitate directly from water.

sedimentary rock

A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together

Sediments

broken pieces of rock, categorized by size

Silicates

Most common mineral family, makes up 90% of the crust, contain silicon and oxygen compound.

Solidification

The cooling of magma or lava to form igneous rock.

Streak

color of a mineral's powder left behind on a ceramic plate. One of the physical properties of minerals useful in identification. Especially for metallic minerals.

sulfides

A non-silicate group of minerals that contains sulfur as part of the compound

Weathering and Erosion

Processes that break down a rock to form sediments.

Honkin

a very large mineral sample

Peridotite

Dense, dark igneous rock that makes up the mantle.

Differentiation

the separation of materials based on density

Moho

boundary between crust and mantle