Earth science

• Mineral


  A solid, inorganic, naturally occurring substance with a crystalline structure and definite chemical composition
• Properties of minerals


  • Solid
  • Inorganic
  • Naturally occurring
  • Crystalline structure
  • Definite chemical composition
• Rock-forming minerals


  Minerals that are one of the most abundant on Earth's crust, one of the first present during rock formation, and important for rock classification
• Most common rock-forming mineral groups

  • Silicates (e.g. feldspar, quartz)
  • Oxides (e.g. hematite, magnetite)
  • Carbonates (e.g. calcite, dolomite)
• Properties used to identify minerals

  • Color
  • Luster
  • Streak
  • Cleavage
  • Fracture
  • Hardness
  • Specific gravity
  • Crystal shape
  • Fluorescence, taste, smell, radioactivity
• Mineral properties


  • Color: Quartz can be colorless, pink, rose, or purple

  Luster: Metallic, glassy (vitreous), dull
• Identifying properties of table salt (halite)


  Observe color

  Observe luster

  Observe streak

  Observe cleavage

  Observe fracture

  Observe hardness

  Observe specific gravity

  Observe crystal shape
• Cleavage surfaces


  Have fracture
• Hardness


  The hardness of a mineral is its resistance to being scratched. It follows the Mohs Scale of Hardness where talc has 1 (softest) and diamond has 10 (hardest)
• Specific gravity


  The specific gravity of a mineral describes the density of the mineral
• Crystal shape


  Minerals have specific crystals if they have time to form crystals. They can be a very useful property in identifying minerals
• Other properties used to identify minerals

  • Fluorescence
  • Taste
  • Smell
  • Radioactivity
• Color


  Property of table salt (halite)
• Streak


  Property of table salt (halite)
• Luster


  Property of table salt (halite)
• Taste


  Property of table salt (halite)
• Hardness


  1. 2.5 for table salt (halite)
• Crystal form


  Cubic for table salt (halite)
• Chemical composition (formula)


  Property of table salt (halite)
• Specific gravity


  Light (2.2) for table salt (halite)
• Water is not a mineral
• Diamond is a mineral
• Tawas (gypsum) is a mineral
• Granite is a mineral
• Fossilized bone is not a mineral
• Most abundant group of rock-forming minerals


  • Examples
• Streak


  More reliable for rock identification than color
• Rock-forming mineral


  A mineral that is one of the first minerals present at the time of a crustal rock's formation
• Minerals have several uses in our daily lives
• Minerals and their uses in daily living

  • Halite (salt) for cooking
  • Graphite (pencil) for writing
  • Diamond and gold as jewelry
• Minerals are never part of a living thing
• Quartz is a mineral
• Most abundant group of rock-forming minerals

  • Feldspar
• Calcite and quartz are minerals that look alike
• Color and luster cannot be used to reliably identify calcite and quartz
• Color is the least reliable property in identifying a mineral
• Graphite is a mineral used as a writing material
• Rock-forming minerals are one of the most abundant minerals found on Earth's crust
• Minerals listed on food nutrition labels

  • Calcium
  • Other minerals
• Parent rock


  Can be either sedimentary or igneous, or even another metamorphic rock