Glossary Rocks

Question 1

Minerals

Answer 1

A natural substance that makes up rocks.

Question 2

Magma

Answer 2

A very hot mixture of molten rock and gases, just below the Earth’s surface, that has come from the mantle.

Question 3

Sediments

Answer 3

Matter that settles to the bottom of a liquid.

Question 4

Lithosphere

Answer 4

The outer layer of the Earth, consisting of the upper mantle and crust.

Question 5

Native Elements

Answer 5

Elements found uncombined in the Earth’s crust.

Question 6

Crystal

Answer 6

Highly transparent glass with a high refractive index.

Question 7

Lustre

Answer 7

Appearance of a mineral caused by the way it reflects light. Minerals such as glassy, waxy, metallic and silky.

Question 8

Streak

Answer 8

colour of a mineral as a fine powder, found by rubbing it onto an unglazed white ceramic tile.

Question 9

Hardness

Answer 9

A measure of how difficult it is to scratch the surface of a solid material.

Question 10

Igneous Rock

Answer 10

Rocks that form from the cooling of lava or magma as it is thrown through the air from a volcanic eruption.

Question 11

Extrusive Rock

Answer 11

igneous rock that forms when lava cools above the Earth’s surface

Question 12

Pumice

Answer 12

A pale rock that forms when frothy lava cools in the air. Pumice often floats on water as it is very light and full of holes that once contained gas.

Question 13

Scoria

Answer 13

A dark, igneous rock formed from gassy lava that cools quickly

Question 14

Abrasive

Answer 14

A property of a material or substance that easily scratches another

Question 15

Basalt

Answer 15

A dark, igneous rock with small crystals formed by fast cooling of hot lava. It sometimes has holes that once contained volcanic gases.

Question 16

Obsidian

Answer 16

A black, glassy rock that breaks into pieces with smooth shell-like surfaces

Question 17

Intrusive Rocks

Answer 17

Igneous rock that forms when magma cools below the Earth’s surface.

Question 18

Batholith

Answer 18

Intrusive rock mass that measures more than 100 kilometres across.

Question 19

Granite

Answer 19

A hard, igneous rock with different-coloured crystals large enough to see. It forms slowly below the Earth’s surface.

Question 20

Sedimentary Rocks

Answer 20

Rocks formed from sediments deposited by water, wind or ice. The sediments are cemented together in layers, under pressure.

Question 21

Floodplan

Answer 21

Flat, open land beside a river where sediments are deposited during floods

Question 22

Glaciers

Answer 22

Large bodies of ice that move down slopes and push boulders, rocks and gravel in front of them

Question 23

Metamorphic rock

Answer 23

Rock formed from another rock that has been under great heat or pressure (or both)

Question 24

Moraines

Answer 24

Deposit left by movement of a glacier

Question 25

Sandstone

Answer 25

A sedimentary rock with medium-sized grains. The sand grains are cemented together by silica, lime or other salts.

Question 26

Mudstone

Answer 26

A fine-grained, sedimentary rock without layering

Question 27

Shale

Answer 27

A fine-grained sedimentary rock formed in layers by the consolidation of clay.

Question 28

Siltstone

Answer 28

A sedimentary rock with a particle size between that of sandstone and mudstone.

Question 29

Conglomerate

Answer 29

Sedimentary rock containing large particles of various sizes cemented together.

Question 30

Limestone

Answer 30

A sedimentary rock formed from the remains of sea organisms. It consists mainly of calcium carbonate.

Question 31

Coal

Answer 31

A sedimentary rock formed from dead plants and animals that were buried before rotting completely.

Question 32

Rock salt

Answer 32

A sedimentary deposit formed when a salt lake or seabed dried up. Its main chemical.

Question 33

Metamorphism

Answer 33

The process that changes rocks by extreme pressure or heat (or both).

Question 34

Slate

Answer 34

A fine-grained metamorphic rock formed as a result of moderate heat and pressure on shale.

Question 35

Marble

Answer 35

A metamorphic rock formed as a result of great pressure on limestone.

Question 36

Gneiss

Answer 36

A coarse-grained metamorphic rock formed mainly as a result of great pressure on granite.

Question 37

Mineral Ores

Answer 37

mined to obtain a metal or other chemical within them

Question 38

Mining

Answer 38

extraction of natural resources from the Earth.

Question 39

Environmental impact statement

Answer 39

study of the possible effects of a planned project on the environment

Question 40

Rehabilitated

Answer 40

restored to its previous condition.

Question 41

Overburden

Answer 41

waste rock removed from below the topsoil. This rock is replaced when the area is restored.

Question 42

Open-cut mining

Answer 42

mining that scours out soil and rocks on the surface of the land.

Question 43

Underground mining

Answer 43

mining that uses shafts and tunnels to remove rock from deep below the surface

Question 44

Stone Age

Answer 44

the time beginning about two million years ago during which early humans made implements of stone

Question 45

Alloy

Answer 45

A mixture of a metal with a non-metal or another metal

Question 46

Flint

Answer 46

A fine-grained sedimentary rock which leaves a very sharp edge when broken

Question 47

Percussion flaking

Answer 47

Aprocess in which tool stones such as flint or obsidian were struck with harder stones, such as quartzite, to shear large flakes that could be used to make small tools