Rocks and Minerals

• What is a mineral?


  A mineral is a solid matter possessing a definite chemical structure that occurs naturally and does not have life.
• How are minerals related to rocks?

  Some rocks are composed of two or more minerals.
• What is the building block of minerals?

  The building block of minerals is an atom.
• What determines the atomic number of an element?

  The number of protons in an atom's nucleus determines its atomic number.
• What are the key considerations about minerals?

  • Occur naturally
  • Inorganic (never alive)
  • Internal structure in an orderly pattern
  • Definite chemical composition
• What are the properties of minerals used to identify them?

  • Crystal form
  • Luster
  • Color
  • Streak
  • Hardness
  • Cleavage
  • Fracture
  • Specific gravity
• What does crystal form describe in minerals?

  Crystal form describes the growth pattern of the crystals of the mineral species.
• What determines the crystal form of a mineral?

  The crystal form is largely determined by the environmental conditions under which a crystal develops.
• What does luster refer to in minerals?

  Luster refers to the quantity and quality of light reflected from the surface of a mineral.
• What are the types of luster in minerals?

  The types of luster include metallic, non-metallic, and submetallic.
• What is the characteristic of metallic luster in minerals?

  Metallic luster refers to minerals that are opaque and very reflective, possessing a high absorptive index.
• What are the types of non-metallic luster?

  Non-metallic luster can be vitreous, pearly, silky, resinous, or earthy.
• What is the visual perceptual property of a mineral called?

  Color is the visual perceptual property corresponding in humans.
• What is streak in minerals?

  Streak is the color a mineral displays when it has been powdered.
• How is hardness defined in minerals?

  Hardness defines the level of difficulty with which the smooth surface of the mineral can be scratched.
• How is hardness determined in minerals?

  Hardness is determined by rubbing the mineral against common objects like fingernails or a penny.