Transcript Mineral
What is a mineral? Mineral- a naturally occurring, inorganic, solid that has a specific crystal structure and chemical composition. 1)Naturally occurring- made by the earth 1)Mineral/ quartz, sulfur, diamond, gold, silver 2)Not a mineral- coal, brick, glass, steel 2)Inorganic- made of nonliving material 3)Specific Chemical Composition- the elements that make the minerals have a definite chemical formula. 4)Crystal Structure- the pattern that the particles form over and over again creating the shape of the mineral Characteristics to classify minerals: 1.Color 2.Streak- the powder of the minerals 3.Luster- the way a mineral shines 4.Density-heaviness 5.Hardness- scratch glass, scratch steel, can scrape with fingernails... 6.BreaksCleavage Color Sulfur Orthoclase Feldspar Amethyst Quartz Rose Quartz Streak- the powder of the minerals. Streak is determined by scraping the mineral on a streak plate and observing the color left on the plate. Luster- the way a mineral shines or reflects light. Types of lusters to select from: Metallitic luster-(graphite) Dull luster (kaoloinite) Glassy luster-(quartz) Waxy, pearly, greasy(talc) Density- how heavy the mineral Galena- extremely heavy mineral Hardness- if the mineral can scratch things or be scratched. Test using Mohs Hardness Scale How the mineral Breaks- a minerals breaks in two ways: 1. Cleavage- when a mineral splits into a pattern because of the arrangement of the atoms. Mica- breaks in thin sheets Calcite-squared edges Halite is cubic 2. Fracture- the minerals breaks in no specific or irregular way. Rose quartz Hematite Olivine Other Properties Some minerals have other unique characteristics that determine the name. Sulfur smells like rotten eggs Magnetite is magnetic Florescence- glows under UV lights Halite tastes salty Franklin County NJ has the most Florescent mineral mined collection in the world!!!! Rocks What is the difference between rocks and minerals? Rocks are made up of mixtures of minerals and other materials. -Example: Granite is made up of... Quartz Hornblend Orthoclase Feldspar Igneous Rocks Rocks that are formed from magma (melted rock under the earth’s surface) or lava (melted rock on the earth’s surface). Two Types of Igneous Rock Intrusive Extrusive formed inside the earth(magma) formed on the earth (lava) Granite Obsidian Scoria Gabbro Pumice Texture and Crystals of rocks of Igneous Rocks A. Texture- the size of the grains that make up the rock Coarse Grain (large grains) Granite Fine Grain (small grains, like sand) Basalt No Crystals- cooled too quickly for crystals to form Obsidian B. Crystals- depends on how fast the rocks cooled Volcanic (from lava)- shot from a volcano, cool to quickly for crystals to form From Magma- magma cools slowly allows the crystallized minerals to form Three Types of Sedimentary Rocks: A. Clastic- formed from pieces/fragments of rocks being squeezed together. Sandstone Examples: Conglomerate B. Organic- made from remains of plants and/or animals. Limestone Shale C. Chemical- formed from minerals dissolving in water and the forms into crystals. Limestone Geodes Sedimentary Rocks Rocks that are formed through a series of processes: erosion, deposition, compaction and cementation. Erosion- particles carried away by wind or water. Deposition- particles placed in an area. Compaction- particles squeezed under pressure. Cementation- particles are glued together Metamorphic Rocks Rocks that change under the Earth’s surface from heat and pressure. Characteristics of metamorphic rocks: Foliated-layers Gneiss Nonfoliated- no layers Marble Rock Cyclea series of processes on the earth’s surface and under the surface that slowly change rocks from one type to another.