Minerals & RocksWhere they come from, what they’re made of, and how you can tell!

Geologistsscientists who study nonliving parts of the earth and divide the earth into layers

Three Main Levels of the EarthCore: center of the earth made of mostly iron Mantle: middle layer made of magma (melted rock) Crust: thin layer on the outer surface of the earth (made up of many pieces

What causes the Earth to move? Scientists think that changes in the magma from the mantle (middle layer) cause areas of the crust to move (as in volcanoes and earthquakes)

Beno GutenbergBorn Jewish in 1889, he studied earthquakes. He is known for determining the size of the earth’s core. He also worked on the Richter scale to measure earthquakes.

WeatheringWearing away of soil and the earth’s crust through EROSION from wind, water, heat, and movement

Sedimentsmall bits of weathered rock that are often picked up by wind and water and moved from place to place

Soilthe loose material on the surface of the earth that is made of weathered rock and other materials

Organicparticles in soil that were once part of a living thing (organic means alive) HUMUS forms from decayed plants and animals

Soil Forms Layers Like the earth, soil forms layers and levels. Plants grow on the top layer (TOPSOIL). Particles get larger and larger the lower you go. There are large rocks if you dig down deep.

Minerals in the EarthMineral: inorganic substance made up of earth’s crust/rock Inorganic: not alive Mineralogist: a scientist who studies minerals

Crystal StructureCrystal: forms from heat and pressure on particles in the earth to create a new form *Larger crystals happen when minerals harden slower *Each mineral has its own crystal structure

Color & StreakColor: in minerals is caused by particles within it Streak Tests: the color of the mark a mineral makes on a surface

LusterLuster: the way a mineral reflects light Dull: little light reflects Metallic: shiny Pearly: clouded/milky Brilliant: light and color show

Hardness Hardness: how easily a mineral resists being scratched *Fredrich Moh’s created a scale of scratch testing minerals

Cleavage and FractureCleavage: breaking of a mineral along smooth, straight lines or flat sheets *Cleavage can be in one, two, or multiple directions

Uses of Minerals

Gemstonea mineral that can be cut and polished, it is called a gem

Precious vs. Semi-Preciousa precious stone is a gemstone that is very rare

a semi-precious stone is a more common stone to find

Syntheticreal gems form naturally, but a copy of the formation of a gem is called synthetic (man made)

synthetic gems are not as valuable as natural stones

Oresmetals that are found in rocks

smeltingwhen ore is crushed and heated, the metal separates from other rock materials

Pipea vertical vein that forms in the shaft of a volcano

pipes often contain diamonds or other minerals formed deep in the earth

Lapidaryskilled craftsman that know the best way to cut each type of gemstone

Examples of Minerals and Their Uses

Gemstones: used to make jewelry or statues (sapphires, diamonds, jade, amethyst, garnet, opal …)

Metals: used to make wires, pipes, bullets, planes, cars (copper, iron ore, titanium, gold, silver …)

Others: some are used to make everyday vitamins and even toothpaste (fluorite, calcite … )

Rocks

What is a rock?A rock is a naturally hard substance made up of one or more minerals

Igneous RockA type of rock that forms from volcanic magma or lava.

Most igneous rocks are very, very hard.

Igneous Rocks We Should Know*Granite:quartz, feldspar, mica, hornblende *Pumice: lava foam that hardens *Obsidian: quickly cooling lava rock that is like shiny, black glass *Basalt: tightly packed, hard, six-sided columns of rock

Sedimentary RockA type of rock that forms in layers of sediment and organic materials that harden together.

Sedimentary Rocks We Should KnowSandstone: formed by smaller sediments that are similar in size Conglomerate: rocks that are made up of sediments that cement together Coal: forms from decayed plant matter Calcite: mineral that forms from animal bones and shells Limestone & Chalk: made of calcite, they weather easily

Metamorphic RockIgneous and Sedimentary rocks that are changed deep below the earth’s surface from heat and pressure

Metamorphic Rocks We Should KnowFoliated: metamorphic rocks that can split and break apart into sheets easily Slate: forms from metamorphic rock shale Non-Foliated: metamorphic rocks that don’t split easily Marble: heat and pressure form this from limestone