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Tuesday November 02, 2010. Update your planner. Set up your Cornell notes. Today’s Theme: What is a mineral? What are the ways that minerals can be identified? What defines whether something is a mineral or not? What is a crystal? What is the difference between a rock and a mineral?
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Tuesday November 02, 2010 • Update your planner. • Set up your Cornell notes. • Today’s Theme: What is a mineral? • What are the ways that minerals can be identified? • What defines whether something is a mineral or not? • What is a crystal? • What is the difference between a rock and a mineral? • Hand in any late work • Progress Reports Tomorrow (Due Thursday) • Science Fair Complete Write Up Due Friday!!!!!!!!! OMG
Friday November 05, 2010 • Open books to page 66. • Turn in science fair project.
Minerals • Today: Use your keen powers of observation to make a list in your notebook of all of the physical properties you notice about the seven samples. • Think about these questions: • Are they all minerals? • Why do they look the way they do? • How did they form? • What are they composed of? • Where did they come from?
Grouping Physical Properties 5 Minutes • How many different ways can you put these samples into different groups • See how many you can think of and write them down • We will share them with the rest of the class
Wednesday November 03, 2010 • Please write today’s lesson and date in your notebook. • Today’s lesson: How do we identify minerals? • What are the physical properties of minerals? • How do we tell minerals apart? • Why do minerals have different properties • Textbooks open to Page 70 • Please do not touch equipment yet!!!! • Science Fair Complete Write Up is due Friday.
Properties of Minerals • Learning Objectives • What are the ways that minerals can be identified? • What is Moh’s Hardness Scale? • What is the difference between cleavage and fracture? • What are some common uses for minerals?
What is a mineral? • A mineral is • Naturally Occurring (made by earth-not man made), • Inorganic (never was alive), • Solid (atoms in fixed position, definite volume/shape), • with a definite crystal structure (repeating pattern of minerals atoms), • and a definite chemical composition (same elements throughout in a certain proportion)
Which of these are minerals? AMBER COAL MICA PEARL QUARTZ SUGAR HALITE
Physical Properties of Minerals • These properties are used to identify minerals
1. Color • Color is the most noticeable physical property of a mineral but is THE LEAST reliable. • This is because the same mineral can come in many colors. Example:
Mineral Identification azurite Color is one physical property that can be used to identify minerals but beware…… rhodochrosite malachite turquoise
2. Streak: The color of the powdered form of a mineral when rubbed on an unglazed porcelain plate
Streak • The mineral is rubbed on an unglazed porcelain plate to determine the color of the streak powder. • Not all minerals have a streak. Any mineral harder than the plate (7+) will leave a scratch instead.
3. Luster • Luster describes how light is reflected from a mineral’s surface. • A mineral has either • Metallic Luster (shines like a metal) or • Non-Metallic Luster. • Dull, earthy, waxy, greasy, pearly, silky or vitreous (glassy)
Luster: The mineral Galena has a metallic luster
Metallic Luster Non-Metallic Luster Examples of Luster
Density • Density is the comparison of mass to volume. • It’s really how well packed are the atoms in the object. Mass divided by volume
Thursday November 04, 2010 • Please write today’s lesson and date in your notebook. • Today’s lesson: How do we identify minerals? • What are the physical properties of minerals? • How do we tell minerals apart? • Why do minerals have different properties • Textbooks open to Page 72 • Please do not touch equipment yet!!!! • Science Fair Complete Write Up is due Friday.
Physical Properties that Identify Minerals (so far) • Color • Streak • Luster (metallic or non-metallic) • Density • Hardness • Crystal Systems • Texture • ……the rest today
5. Hardness • Hardness is a measure of how easily a mineral is scratched. • determined by arrangement of the mineral’s atoms.
Mohs Hardness Scale:a relative scale used to determine the mineral’s hardness 5.5 4.5 3.5 6.5 2.5 Fingernail Penny Iron Nail Glass Streak Plate
Crystal Systems • The way the mineral grows atom by atom makes a shape we call a crystal. • Most of the time you can’t see them. • More time and space it had to grow = bigger crystals
Crystal Forms These are Quartz Crystals • These are Quartz Crystals
7. Texture • Texture describes how a mineral feels to the touch. • Texture can be described as greasy, soapy, glassy, rough, ragged or smooth. • Graphite has a greasy texture.
Cleavage or Fracture • The way minerals break. • Cleavage - When Minerals break along planes (layers) where bonding between atoms is weak. • A mineral that splits or breaks easily along smooth, flat surfaces is said to have cleavage. • Mica has perfect cleavage in one direction (plane). • Halite has cubic cleavage (3 planes).
Three Examples of Perfect Cleavage – Fluorite, Halite & Calcite
Cleavage or Fracture • Minerals that break along rough, jagged or uneven edges and surfaces are said to have fracture. • conchoidal (shell-like), splintery, uneven, jagged or earthy Conchoidal Example : Quartz
Don’t be confused between CrystalFaces (sides) and Cleavage Planes!- Both minerals in these pictures show Fracture (not cleavage) These are Quartz Crystals These are Quartz Crystals
Special Properties • Specific gravity • Reaction to acid • Striations (lines) • Magnetism • Fluorescence • Refraction
Uses of Minerals • Gems or Gemstones are highly prized minerals because they are rare and beautiful. • An Ore is a mineral that contains a useful substance that can be mined at a profit. Ore NameGives Us Hematite Iron Chalcopyrite Copper Bauxite Aluminum Sphalerite Zinc
Uses of Minerals Gems: Valuable minerals prized for rarity and beauty. Ores: Minerals that can be mined at a profit.
Uses of Minerals • http://www.minsocam.org/MSA/K12/uses/uses.html • http://www.emporia.edu/earthsci/amber/go336/talkingt/