Minerals Building blocks of rocks and our Earth. Chapter 29 section 3.

Minerals

Building blocks of rocks and our Building blocks of rocks and our Earth.Earth.

Chapter 29 section 3Chapter 29 section 3

What is A Mineral? Mineral - a solid, naturally-occurring,

inorganic element or compound with defined chemical composition. They are also crystalline in structure. Based on regular arrangement of atoms or ions within it.

Rock forming minerals very common on Earth’s surface The 20 most common make up 95% of

Earth’s crustQuartz, and orthoclase feldspar are the

most common Silicate minerals – minerals containing

atoms of silicon (Si) and oxygen (O). Nonsilicate – minerals that do not contain

Si. There are 6 groups.

Crystalline Structure

Crystal – natural solid with definite internal pattern.Large crystals show internal

structureIf crystal forms in UNRESTRICTED

environment a single large crystal WILL develop.

Identifying Minerals Characteristics of Minerals – minerals are

identified by their properties.Color- the color of it. Color is unreliableLuster- the way light is reflected from

fresh surface of the mineralMetallic: looks like polished metal.Nonmetallic: glasslike, waxy, pearly,

brilliant (diamond), dull or earthy, and many more.

Identifying Minerals Streak- color obtained when mineral is

rubbed across the surface of an unglazed porcelain tile. Streak is more important than color

mineral true color. Cleavage - tendency of mineral to split on

flat surfaces. Fracture – tendency of mineral to break

unevenly

Identifying Minerals Hardness - Resistance of a mineral to

scratching Moh’s Scale of Mineral Hardness.19th century German mineralogist,

Friedrich Moh. Know the chart on page 578.

Identifying Minerals . Common materials to estimate hardness

fingernail-hardness about 2.5copper penny-hardness 3 to 3.5steel nail-hardness 5 to 5.6window glass-hardness 5.5 to 6

Rocks

Types of Rocks

Sedimentary Rocks

Metamorphic RocksIgneous Rocks

Types of Igneous Rocks

Intrusive: Formed underground by trapped, Intrusive: Formed underground by trapped, cooled magma, large mineral crystalscooled magma, large mineral crystals

Extrusive: Formed above ground when Extrusive: Formed above ground when volcanoes erupt and magma cools, smaller volcanoes erupt and magma cools, smaller mineral crystals.mineral crystals.

Examples of Igneous Rocks

Granite Scoria

ObsidianDiorite

Intrusive Igneous Extrusive Igneous

Sedimentary RocksHow They are Made

Wind and water break down the earthWind and water break down the earth Bits of earth settle in lakes and riversBits of earth settle in lakes and rivers Layers are formed and build upLayers are formed and build up Pressure and time turn the layers to rockPressure and time turn the layers to rock

Sedimentary Rock Classification

Clastic – composed of fragments (clasts) of Clastic – composed of fragments (clasts) of pre-existing rock transported some distance pre-existing rock transported some distance from their points of originfrom their points of origin

Chemical – form when standing/trickling Chemical – form when standing/trickling water evaporates, leaving dissolved water evaporates, leaving dissolved minerals behind. minerals behind.

Organic – an accumulation of sedimentary Organic – an accumulation of sedimentary debris caused by organic processes. Plants debris caused by organic processes. Plants and animals. and animals.

Types of Sedimentary Rocks

Gypsum Chemical

Sandstone Clastic

Shale Clastic

Limestone Organic

Conglomerate Clastic

Metamorphic Rocks Rocks that have changedRocks that have changed They were once igneous or They were once igneous or

sedimentarysedimentary Pressure and heat changed the Pressure and heat changed the

rocks rocks 2 types: Regional and Contact2 types: Regional and Contact

Contact occurs near magma Contact occurs near magma chamberschambers

Regional occurs where Regional occurs where continents collidecontinents collide

Types of Metamorphic Rocks

Marble Gneiss

Rocks Have Been Used For Many Years

and For Many Things

Rocks