Rocks and Minerals http en wikipedia orgwikiFile USDAMineralSandstone93

Rocks and Minerals http: //en. wikipedia. org/wiki/File: USDA_Mineral_Sandstone_93 c 3955. jpg http: //www. beg. utexas. edu/mainweb/publications/graphics/granite. htm http: //www. gccaz. edu/earthsci/imagearchive/gneiss. htm

Minerals In order for a substance to be consider a mineral, it must have the following 5 characteristics: üMust be solid üMust be inorganic üMust be naturally occurring üMust have a definite chemical composition üMust have a definite crystal shape

• Minerals are the basic building blocks of all rocks. • Oxygen is the most abundant by mass and volume (46%, 94%) • Silicon is second in mass (28%)

Mineral Properties • All mineral properties are determined by the INTERNAL ARRANGEMENT of ATOMS

Please grab the three (3) pieces of paper on the side of the room. Using a blue or black pen, please fill out the STEM survey.

Properties • Color – easiest property to identify but the most useless • Many minerals have the exact same color but are completely different.

Properties • Luster – the way the mineral shines in reflected light • Two types – • Metallic – Looks like metal, gold or silver in color • Nonmetallic – Doesn’t look like metal

Properties cont’d • Streak – color of the minerals powder when rubbed on a streak plate. • Will not always be the same color as the mineral sample • Example – Pyrite is gold in color but has a green/black streak

Properties cont’d • Cleavage – the tendency of a mineral to break, or cleave, in a flat plane -

Properties cont’d • Fracture – Irregular breakage • Looks a lot like breaking apart a clod of dirt or a cookie. • No pattern of breakage

Properties cont’d • Hardness – resistance to being scratched • Follows Moh’s Hardness Scale

Types of Minerals • Silicates – made up of primarily silicon and oxygen • Silica Tetrahedron – basic building blocks of all silicates (Si. O 4)

Other types of Minerals • Carbonates - • Iron Oxides -

Common Uses • Feldspar – used in ceramic and glass products, fertilizers, and soaps • Gypsum – used in drywall and plaster applications, cement, and fertilizer • Quartz – used in electronics, jewelry, and in powder form can be used as a thickening agent • Mica- used as electrical insulators, and as bonding agents in paints and flux in welding rods • Fluorite – used to make hydrofluoric acid, and powdered as a fluorine agent in municipal water systems and toothpaste • Sulfur – used in manufacturing processes, such a drug production and vulcanization of rubber

IGNEOUS ROCKS • Form by solidification and crystallization of melted minerals • Plutonic – formed underground • Also known as intrusive • - Cools slowly- LARGE CRYSTALS • - texture will be considered coarse

Volcanic – forms aboveground - also known as extrusive - Quick cooling means fine to no crystals - Texture is considered fine or glassy

Obsidian • Natural volcanic glass • Forms when lava cools very quickly • Usually dark, but small pieces may be clear • Fractures along curved (conchoidal) surface • Used as spear and arrow points, knives

Types of Magma - Felsic – - light in color - low in density - contains a lot of feldspar - Rocks include granite, pegmatite, and pumice

-Mafic - - dark in color - high in density - contains a lot of iron - Rocks include Gabbro, Basalt,

Vesicular – gas pockets

Rock Texture- texture is determined by crystal size not how the rock feels -NO ONE CARES HOW YOU FEEL when it comes to texture

Igneous Characteristics-MEMORIZE ME 1. Visible Scattered Crystals 2. Glassy texture 3. Visible gas pockets (vesicular)

Sedimentary Rocks Sedimentary Rock- formed from compaction and cementation of sediments or living organisms THREE MAJOR TYPES

Sedimentary Rocks - Clastic (fragmental) – made of sediments of other rocks that have been broken down - Classified by the size of the sediments that make up the rock

Sedimentary Rocks

Sedimentary Rocks Chemical(crystalline)- forms when water dissolves minerals, evaporates and leaves the mineral behind

Sedimentary Rocks Bioclastic (Organic) – made from the parts of living things, such as plants and animals

Sedimentary Rocks Processes that create sedimentary rocks - Compaction- pressing of sediments together by force

Sedimentary Rocks Cementation- gluing sediments together with some sort of natural process Super Cool Totally Groovy Cementation Animation

Sedimentary Rocks Stratification- when sediments pile up in layers

Sedimentary Rocks Fossils – evidence of life, often found in sedimentary rocks

Characteristics of Sedimentary Rocks 1. Visible Sediments

Characteristics of Sedimentary Rocks 2. Dull, Earthy colors

Characteristics of Sedimentary Rocks 3. Visible fossils

Characteristics of Sedimentary Rocks 4. Sediments in layers

ESRT- Sedimentary Rocks

Metamorphic Rocks • Formed by heat and pressure changing existing rocks • Regional – metamorphism that occurs over a large area that is exposed to heat and pressure • - causes severe metamorphism

Regional Metamorphism- Metamorphic Rocks

Regional Metamorphism- Metamorphic Rocks Contact- change that occurs when rocks come in contact with heat only - Subtle changes - Deformation only

Characteristics of Metamorphic Rocks 1. Bands of Crystals (color bands)

Characteristics of Metamorphic Rocks 2. Deformation

Characteristics of Metamorphic Rocks 3. Foliation- crystals in flaky layers

ESRT: Metamorphic Rocks

Rock Cycle

Content resources • • • Diamond/Graphite Image: http: //chemistry. tutorvista. com/organic-chemistry/carbon-compounds. html Sulfur - http: //depthome. brooklyn. cuny. edu/geology/core 332/minerals. htm Pyrite-http: //mineralminers. com/html/pytmins. stm Kaolin - http: //www. library. csi. cuny. edu/dept/as/mineral/nmws. htm Streak Image - http: //skywalker. cochise. edu/wellerr/mineral/hematite/6 hematite-streak 10. jpg Calcite - http: //skywalker. cochise. edu/wellerr/mineral/calcite 6. htm Cleavage - http: //www. minerals. net/mineral_glossary/cleavage. aspx Fracture - http: //geology. com/minerals/photos/quartz-conchoidal-482. jpg Moh’s Scale - http: //www. visionlearning. com/library/modules/mid 130/Image/VLObject-3337 -050515120556. gif Moh’s Image - http: //www. contempofloorcoverings. com/wp-content/uploads/2010/05/Mohs-Hardness-Scale. jpg Silica Tetrahedron - http: //www. all-around-us. com/images/sci/st-sio 4 m. jpg