Planet Earth Minerals Rocks and the Rock Cycle Erosion The Moving Crust Earthquakes Volcanoes Mountains Fossils Geologic Time Fossil Fuels

Minerals Topic 1

Minerals – Introduction Rocks contain naturally occurring, non-living substances called minerals. Minerals are rare and are either: elements (made of 1 type of atom) or compounds (combinations of bonded atoms) Minerals are not only found in rocks, but they are also found in your body, and dissolved in water (like iron and potassium) Mineral Uses - first 1:40

Think about it! How might you tell these two minerals apart? One is pyrite (fool’s gold) the other is actual gold – can you tell the difference? Geology Kitchen - Identifying Minerals

Identifying Minerals Minerals can be identified 5 main ways: Colour & Streak Hardness Shape & Crystals Lustre Cleavage & Fracture (Chemical Properties, Transparency & Density) Mineral Properties

Colour & Streak Some minerals can be identified by looking at the colour of the surface. One Mineral may have several colours Corundum can be white, blue or red, depending on what other elements are present.

Colour & Streak When two different minerals appear to have the same colour, streak can be used to show the colour of the powder form of the mineral

Hardness Fredrick Mohs was a German scientist from the early 1800’s He developed a scale of ten minerals to show hardness Talc is the softest mineral – similar to pencil lead Diamond is the hardest mineral – used on surgical scalpels, razor blades and drill bits

Hardness – Mohs Scale

Hardness – Mohs Scale Mineral Hardness Hardness of Common Objects Talc 1 Soft pencil (1) Gypsum 2 Fingernail (2.5) Calcite 3 Copper (3.5) Fluorite 4 Iron Nail (4.5) Apatite 5 Glass (5.5) Feldspar 6 Steel File (6.5) Quartz 7 Porcelain Tile (7) Topaz 8 Flint Sand Paper (7.5) Corrundum 9 Emery Paper (9.0) Diamon 10 Carborumdum Sandpaper

Shape & Crystals Crystals are the building blocks of minerals They are natural structures with flat faces, straight edges Most minerals will grow into huge crystal formations

Shape & Crystals

Lustre Lustre is the shine of a surface, or the way it reflects or absorbs light. Lustre is split between metallic and non-metallic

Lustre

Cleavage & Fracture Cleavage is when minerals split along the flat surfaces of the crystals Fracture is when minerals break along uneven surfaces Mica has cleavage because it breaks in smooth flat sheets

Chemical Properties Some minerals will react with substances like acids Calcium carbonate (aka chalk) reacts with acids and produces a new gas, so it bubbles Another chemical property is that metals corrode when exposed to oxygen in the air. This is called rust, or oxidization

Transparency Minerals can also be identified by the amount of light they let through. They can be: Transparent – see through Translucent – shadowy Opaque – no light passes through

Density Density relates to how many particles are in a given amount of a mineral. If there are a lot, the mineral will seem quite heavy compared to a less dense mineral which can seem light. Some lava rock is so light that it can float. This contributes to the formation of volcanic islands like Hawaii

Rocks & The Rock Cycle Topic 2

The Rock Cycle There are three types of rocks Igneous Sedimentary Metamorphic

Igneous Rocks Igneous rock forms when hot magma or lava cool and solidify Magma is melted rock found below the Earth's crust Rocks made of magma are INtrusive igneous rocks Lava is molten rock that is on the earths surface (after volcano) Rocks made of lava are EXtrusive igneous rocks

Igneous Rocks Cooling magma and lava will create crystals The size of the crystals depends on how fast the rock cools The slower it cools, the larger the crystals

Igneous Rocks - Intrusive Granite is an intrusive igneous rock Tiny crystals are visible in the rock

Igneous Rocks - Extrusive Obsidian is an extrusive igneous rock The crystals are too small to be seen because of how quickly the rock cooled. Igneous Rocks

Sedimentary Rocks Sediment is small loose pieces of material like rocks, minerals, and organic matter Sediment forms into sedimentary rock over time.

Sedimentary Rocks Sedimentary rock is made up of layers of compressed sediment, cemented together over time The cementation happens when certain minerals dissolve in water and bind the sediment when it dries.

Sedimentary Rocks 75% of the rock on the Earth’s surface is sedimentary Visible layers of sedimentary rock are called strata

Sedimentary Rocks Types of sedimentary rock include: Shale comes from fine clay or mud Sandstone comes from broken down quartz Conglomerates are pebbles and small stones cemented together Limestone is organic sedimentary rock, containing fossils Sedimentary Rocks

Metamorphic Rocks Meta – Change Morph – shape/form Metamorphic rocks are those that have changed form because of heat and pressure that have been applied to the parent material.

Metamorphic rocks Shale  Slate  Schist Granite  Gneiss Limestone  Marble Metamorphic Rock

Metamorphic Rocks

The Rock Cycle Rocks are constantly changing. The Rock Cycle varies constantly as rocks are: Weathered Compression and Cementation Buried Melted Solidified Sung Pet Rock Theatre