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• Minerals


  Naturally occurring inorganic solids that possess an orderly crystalline structure and can be represented by a chemical formula
• Minerals are the building blocks of rocks
• Minerals have been employed by humans for both useful and decorative purposes for thousands of years
• Early minerals mined

  • Flint
  • Chert
• Minerals mined by Egyptians as early as 3700 BC

  • Gold
  • Silver
  • Copper
• Humans discovered how to combine copper with tin to make bronze, a strong, hard alloy
• By about 800 BC, iron-working technology had advanced to the point that weapons and many everyday objects were made of iron rather than copper, bronze, or wood
• During the Middle Ages, mining of a variety of minerals was common throughout Europe, and the impetus for the formal study of minerals was in place
• Mineral (as used by geologists)


  Naturally occurring inorganic solid that possesses an orderly crystalline structure and can be represented by a chemical formula
• Characteristics of minerals


  • Naturally occurring
  • Solid substance
  • Orderly crystalline structure
  • Generally inorganic
  • Can be represented by a chemical formula
• Rocks are more loosely defined as any solid mass of mineral, or mineral-like, matter that occurs naturally as part of our planet
• Most rocks are aggregates of two or more minerals
• The properties of rocks are determined largely by the chemical composition and crystalline structure of the minerals contained within them
• Atom


  Smallest particle that cannot be chemically split
• Atoms


  • Contain protons, neutrons, and electrons
  • Protons and neutrons are very dense particles with almost identical masses
  • Electrons have a negligible mass, about 1/2000th that of a proton
• Electrical charge

  Protons have a charge of +1, electrons have a charge of -1, neutrons have no charge
• Matter typically contains equal numbers of positively charged protons and negatively charged electrons, so most substances are electrically neutral
• Valence electrons


  Electrons in the outermost shell that interact with other atoms to form chemical bonds
• Element


  Group of the same kind of atoms, determined by the number of protons in the nucleus
• There are about 90 naturally occurring elements and 23 that have been synthesized
• Periodic table


  Arrangement of elements organized so that those with similar properties line up in columns
• A few minerals are made entirely of atoms of only one element, but most minerals are chemical compounds composed of atoms of two or more elements
• Ionic compounds


  Atoms bonded together by electrical attractions
• Molecules


  Atoms bonded together
• Metallic substances


  Atoms bonded together in a metallic structure
• Electrical forces hold atoms together and bond them to each other, lowering the total energy of the bonded atoms
• A few minerals, such as native copper, diamonds, and gold, are made entirely of atoms of only one element
• Most elements tend to join with atoms of other elements to form chemical compounds
• Most minerals are chemical compounds composed of atoms of two or more elements
• The three main particles of an atom

  • Protons
  • Neutrons
  • Electrons
• Valence electrons are generally involved in chemical bonding
• Except for a group of elements known as the noble gases, atoms bond to one another under the conditions (temperatures and pressures) that occur on Earth
• Ionic bond


  The attraction of oppositely charged ions to one another, producing an electrically neutral compound
• Covalent bond


  A chemical bond formed by the sharing of a pair of electrons between atoms
• Metallic bond


  The valence electrons are free to move from one atom to another so that all atoms share the available valence electrons
• Isotope


  Atoms with the same number of protons but different numbers of neutrons
• In chemical behavior, all isotopes of the same element are nearly identical
• Many elements do have isotopes in which the nuclei are unstable and undergo radioactive decay
• Radioactive atoms are used to determine the ages of fossils, rocks, and minerals
• Isotope


  Atoms of the same element that have the same number of protons but different numbers of neutrons