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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