Chapter 7 Rocks and Minerals

Geologist

Studies the structure, rocks, and minerals of the earth

core

the center of the earth

mantle

middle layer of the earth; most of the earth's mass

crust

outer layer of the earth

magma

melted rock that makes up the mantle of the earth

lava

magma that reached the surface of the earth

sediment

small bits of weathered rock

erosion

the movement of sediment from one place to another

weathering

wearing away of the earth

soil

the loose material on the surface of the earth in which plants might grow

organic

particles that were once part of a living thing

humus

organic particles in the soil

mineral

an inorganic substance found naturally in the earth

inorganic

a substance made of things that were not alive

mineralogist

scientist who study minerals

streak

the color of the mark that is made when a mineral sample is rubbed on a harder surface

luster

the way a mineral reflects light

hardness

how easily a mineral is scratched

Mohs scale

a scale used to determine the hardness of a mineral

cleavage

the breaking of a mineral along smooth, straight lines or into flat sheets

fracture

breaking of a mineral that does not break along straight lines

gemstones

a mineral that can be cut and polished for use

precious stone

a gemstone that is beautiful and rare (diamonds, rubies, sapphires, and emeralds)

semiprecious stone

stones which are more common but still vary beautiful (amethysts, garnets, opals, turquoise, jade)

synthetic

man-made gemstone

ore

rocks where metals are found

smelting

the process of melting and separating rock materials from the metal contained in them

Uses of Minerals

toothpaste, fertilizer, dry wall, pottery, electronics, glass, food, drinks, medicine, and paint

lapidary

a person who cuts and polishes gemstones

rock

a hard, natural substance made of one or more minerals

igneous rock

rock that forms from volcanic magma or lava

sedimentary rock

forms when layers of sediment and organic material hardens

conglomerate

a sedimentary rock that looks like pebbles that have been cemented together

metamorphic rock

rock formed by heat and pressure deep below the earth's crust

places in earth minerals can be found

on the surface of earth, buried in the earth's crust, or in veins

limestone and sandstone

sedimentary rocks

slate and marble

metamorphic rocks

obsidian and pumice

igneous rocks

Coal

rock-like substance that forms from decayed plant matter

extrusive igneous rock

rock that forms when lava cools above the surface of Earth

intrusive igneous rock

igneous rock that forms when magma cools below Earth's surface

steps of sedimentary rock formation

Weathering, Erosion, Deposition, Compression, Lithification