Presentation on theme: "Aim: What is a Mineral? Do Now: Minerals are used in everyday life. In your notebooks, try to brainstorm about ways minerals are used by you and me every."— Presentation transcript:
Aim: What is a Mineral? Do Now: Minerals are used in everyday life. In your notebooks, try to brainstorm about ways minerals are used by you and me every day. Examples: make-up, pencils, salt, toothpaste, jewelry, electronics, construction,
I. Minerals: Minerals are classified as… a. Naturally occurring – Forms by natural geologic processes. b. Solid substance c. Orderly crystalline structure – atoms are arranged in an orderly and repetitive manner. Fluorite
d. Definite chemical composition – most are made up of two or more elements. e. Generally considered Inorganic – not living (exception calcite, which comes from living things). Garnet Minerals make up rocks
II. How do Minerals Form? There are 4 major processes by which minerals from: 1. Crystallization - As hot magma cools, elements within the magma combine and harden to form minerals. crystallize = to form a crystal Galena
2. Precipitates - solid substances are dissolved in water. -These substances are left behind or precipitated, from a body of water when the water evaporates, and forms into a mineral. Like Rock Candy or the ring around your bathtub Salt Flat - Halite Limestone Cave
3. Pressure and Temperature - Minerals form when existing minerals are subjected to changes in pressure and temp. *The atoms are morphed or rearranged Sulfur
4. Hydrothermal Solutions - Very hot solutions cause chemical reactions with existing minerals to form new minerals. PyriteQuartz
III. Tetrahedral Crystalline Structure - Silicon and Oxygen combine to form a structure called the Silicon-Oxygen Tetrahedron. This structure is found in Quartz and makes it the most abundant mineral
Review Questions: 1)What are the five characteristics of all minerals? 2)Where does the material come from to undergo crystallization? 3)Explain the process of the formation of a precipitate. Minerals are naturally occurring, inorganic, solids, with definite crystal shape and definite composition. The material comes from the inside of the Earth or a volcanic eruption. The material has to be extremely hot! Material needs to be dissolved in water. Later, the water is evaporated leaving the mineral behind. Solid materials can not be evaporated like water.
Aim: What properties do minerals have? Do Now: How can a scientist tell the difference between different minerals? List some of the properties you would look for to classify a mineral. Use your ESRT page 16 to help determine useful properties. Examples: Luster, hardness, cleavage, fracture, color, use, composition, distinguishing characteristics
I. Properties of Minerals A mineral’s properties depend on: 1) The elements that compose the mineral (composition). 2) How the mineral’s atoms are arranged internally (structure). **All mineral properties depend on the atoms that make-up the mineral**
Take out Page 16 of your ESRT Non-Metallic We will take notes on each section of this table
1. Color - Small amounts of different elements (impurities) can give the same mineral different colors. - Some minerals come in many colors making color a less useful property. Quartz
2. Streak - Streak is the color of a mineral in its powdered form. - Streak is obtained by rubbing a mineral across a streak plate (a piece of porcelain.)
3. Luster - Luster is used to describe how light is reflected from the surface of a mineral. - Metallic vs. Non-Metallic Pyrite Galena Sulfur Feldspar
4. Crystal Form - Crystal form is the visible expression of a mineral’s internal arrangement of atoms. - Every mineral has a distinct crystal form. Calcite
5. Hardness - Hardness is a measure of the resistance of a mineral to being scratched. -The Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest). - Hardness will be determined using a glass plate.
The glass plate should be held flat on the table. A clean un-scratched surface should be determined by rubbing your finger nail on the plate. If you feel a scratch that spot should not be sued for the test. The mineral should be scratched against the glass plate once with some pressure. 1.If it scratches the glass, then the mineral is harder 2.If it doesn’t scratch the glass, then the mineral is softer. Do not copy Copy these last two for your notes on hardness.
6. Cleavage - Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces. Mica Calcite
7. Fracture - Minerals that do now show cleavage when broken are said to fracture. - Fracture is the uneven breakage of a mineral. Sulfur Quartz
8. Distinctive Properties of Minerals - Some minerals can be recognized by other distinctive properties. a.Effervescence - using Hydrochloric Acid on calcium (Calcite.) b. Magnetic (Hematite)
c. Double Refraction d. Fluorescence (Glow in UV light)
Closure/Homework Use your Notes and use your ESRT to answer some of the questions. The answers are on page 16, you need to find them. Review Book page 44-45 # 1-17