Properties of Minerals
Terms
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- What four properties do minerals have?
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1. naturally occuring
2. inorganic
3. chrystal structure
4. definite chemical composition - What does it mean for a mineral to be naturally occuring?
- it's a substance formed by processes in the natural world
- How is quartz an example of a naturally occuring mineral?
- Quartz forms naturally as molten material cools and hardens deep beneath Earth's surface
- Why aren't plastic, brick and glass minerals?
- They are made by people rather than natural forces.
- What does it mean for a mineral to be inorganic?
- A mineral cannot form from materials that were once part of a living thing.
- Why isn't coal a mineral?
- Coal was formed from the remains of plants that lived millions of years ago.
- What does it mean for a mineral to be a solid?
- A solid has definite volume and shape. The particles that make up a solid are packed together very tightly so they can't move around.
- What does it mean for a mineral to have a chrystal structure?
- A chrstal structure occurs when the particles line up in a pattern.
- What does it mean for a mineral to have a definate chemical composition or range of compositions.
- A mineral always contains certain elements in definite proportions.
- What is a compound?
- A combination of two or more atoms that has its own properties or characteristics.
- Are the properties of a compound the same as the properties of the atoms that produce the compound?
- NO
- Are metals pure solid elements or compounds?
- Almost all metals are pure, solid elements.
- How do scientists identify minerals?
- Each mineral has characterisic properties that can be used to identify it.
- In what two ways can you identify the properties of a mineral?
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observing them
conductin tests on them - Why is color a limiting method for identifying minerals?
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Many minerals are the same color, so color can only be used for minerals that are always their own characteristic color.
(Malachite/Azurite) - What is a streak test?
- Rubbing a mineral against a piece of unglazed porcelain tile -- the streak it makes does not vary in color even though the outside color of the stone may.
- Are the streak color and the color of the mineral always the same?
- Not always
- What is luster?
- the term used to describe how light is reflected from a mineral's surface.
- What is density?
- The mass in a given space or mass per unit volume
- Is the mass (size) of the mineral the same as its density?
- NO. No matter what the size of a mineral sample is, the density always remains the same.
- What is the formula for finding density?
- Density = mass/volume
- What is the Mohs harness scale?
- A test to describe the hardness of minerals
- How does the Mohs hardness scale work?
- It ranks ten minerals from softest to hardest.
- How is hardness determined?
- by a scratch test -- a mineral can scratch another mineral that is softer, and can be scratched by one that it harder
- What is a chrystal system
- The way the crystals of each mineral grow atom by atom. The number and angle of the crystal face
- How many chrystal systems are there
- Six
- What are the chrystal systems?
- cubic, hexagonal, tetragonal, orthohombic, monoclinic, and triclinic
- What is fracture?
- the way a mineral looks when it breaks apart in an irregular way
- What are some ways fractures are classified?
- shell-shaped, hackly (jagged and pointy), earthy (easily crumbled), uneven (rough, irregular surfaces)
- What are two special features of minerals?
- magnetism and glowing under an ultraviolet light
- What is a geode?
- a round hollow rick that is often lined with mineral crystals
- What is crystallization?
- the process in which atoms are arranged to form a material with a crystal structure.
- In what two ways can minerals be formed?
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1. by crystallization of molten material
2. by crystallization of materials dissolved in water - What is magma?
- molten material from inside Earth that hardens to form rock
- Lava
- magma that reaches the surface and forms rock when it cools and hardens
- How do minerals form from magma and lava?
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1. hot magma cools inside Earth When it cools it forms crystals
2. Lava hardens on the surface and cools to form crystals - solution
- a mixture in which one substance is dissolved in another
- How do minerals form from solutions?
- When elements and compounds that are dissolved in water leave a solution, crystallization occurs
- Where can minerals form from solutions?
- underground and in bodies of water
- How are minerals formed by evaporation?
- When the solution evaporates, the crystal will be left
- What happens to a mineral that is formed from a hot water solution?
- It forms veins
- Vein
- A narrow channel or slab of a mineral that is differnet from the surrounding rock
- How are veins formed
- Solutions of hot water and metals often flow through crack within the rock, metals crystallize into veins
- What are minerals used for
- gemstpmes, metals, and materials to make many products
- What are gemstones used for?
- They are polished and cut into gems and used for jewelry, mechanical parts and grinding and polishing
- What are some metals that come from minerals?
- aluminum, iron, copper, and silver
- What is the difference between a metal and a gemstone?
- A metal is not as hard as a gemstone
- Why are metals useful?
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They can be:
stretched into wire
flattened into sheets
and hammered or molded without breaking - What are metals used for?
- tolls and machinery, filaments in light bulbs, aluminum foil, and steel beams
- What are some other uses for minerals?
- food, medicine, fertilizer, and building material
- What is talc used for
- powder
- What is quartz used for
- making glass and in electronic equipment and watches
- What is gypsum used for
- wallboard, cement and stucco
- How is a mineral containing metal made into a finished product
- it must be located through prospecting and removed from the ground. Then the rock must processed to extract (take out) the metal
- What is a prospector?
- Anyone who searches for an ore deposit
- How do geologist prospect
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observing rocks on the land surfce
studying maps of rocks beneath the surface
measuring the Earth's magnetic field - What are 3 types of mines
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strip mines
open pit mines
shaft mines - What is strip mining
- The earthmoving equipment scrapes away soil to expose ore
- What is open pit mining
- earthmoving equipment is used to dig a tremendous pit and remove ore deposits
- What is shaft mining
- miners dig a network of tunnels that extend deep into the ground following a vein of ore
- What is smelting?
- the process in which an ore is mixed with other substances and then melted to separate useful metal from other elements the ore contains
- What is an alloy
- A solid mixture of two or more elements at least one of which is a metal. An alloy MUST have the characteristic properties of a metal.