Hardness

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Hardness
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Hardness

• HardnessHow hard it is to scratch a mineral

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Mohs Hardness Scale

• Mohs Hardness ScaleA scale that goes from 1-10
  that tells you how hard a mineral is
• 1 is the softest mineral
• 10 is the hardest mineral
• The scale is relativea mineral that is a 10 on
  the hardness scale isnt 10 times harder than a 1

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Hardness

• A mineral with a higher hardness number will
  scratch a mineral with a lower hardness number
• A mineral with a hardness of 5 will scratch a
  mineral with a hardness of 3

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The hardness scale

• What will scratch it
• Diamond 10
• Corundum 9
• Topaz 8
• Quartz 7 Streak plate- 7.0
• Feldspar 6
• Apatite 5 Steel nail- 5.0
• Fluorite 4
• Calcite 3 Penny- 3
• Gypsum 2 Fingernail- 2
• Talc 1

Softer Harder
6
In other words

• If a fingernail scratches a mineral, it has a
  hardness of 2 or less
• If a penny scratches a mineral, it has a hardness
  of 3.0-2.0
• If a nail scratches a mineral, it has a hardness
  of 5.0-3.0
• If a streak plate scratches a mineral, it has a
  hardness of 7.0-5.0
• If none of the above scratches a mineral, it has
  a hardness of more than 7