Ch. 4: Minerals. Earth’s crust is composed of about 3000 minerals!
Post on 01-Jan-2016
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Minerals
• Help form rocks
• Shape earth’s surface
• Shape our civilization
• Mineral: naturally occurring inorganic solid with specific chemical composition and definite crystalline structure
Identifying Minerals
• Color: least reliable
• Luster: the way it reflects light– Metallic, shiny or non-metallic, dull, or pearly..
• Texture: how does it feel? – Smooth, soapy, rough, greasy
• Streak: color of a mineral when it’s broken up and powdered– Very consistent, only useable on softer
minerals
• Hardness: how easily it can be scratched– Friedrich Moh’s scale– Very reliable
• Density– How tightly compacted
a substance’s molecules are
D = m/v– Less dense than liquid:
floats– More dense than
liquid: sinks
Mineral uses
• Ore: a mineral is an ore if it…– contains a useful substance
AND– can be mined for a profit
Find the answers in ch. 4
• What mineral forms rubies and sapphires? What’s the difference between them?
• Which is more valuable – a diamond or emerald? Why?
• Matter: anything that has volume and mass– Made of elements
• Elements: substance that connot be broken down into smaller substances by physical or chemical means– Purely and completely ______________
Elements
• 92 naturally occuring elements on earth or in stars
• Hydrogen and Helium are the most abundant elements in the universe!
• Why?
In the oceans:
What do you think?
• Sodium
• Chloride
• Hydrogen
• Oxygen
• Why?
• 97% of all water on earth is salt water!
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