Chapter 5: Atoms, Elements, and Minerals
What are minerals?
•Compositionally and physically distinctive substances.
•Develops in a particular way under natural conditions such as heat,
pressure, oxygen, available atoms, and acid content determine how
minerals are formed.
•4500 kinds of minerals in the world- only a couple hundred that are
common and a couple dozen that for the majority of all rocks.
•Distinguished by properties such as, colour, luster, hardness, chemical
composition and the transmission of light under a microscope.
•Crystals are “perfectly formed’ minerals. Consist of faces, edges and
•A geode–pocket of volcanic rocks–forms crystals with faces that reflect
•There are 230 different kinds of symmetrical arrangements in nature.
•Minerals are said to be crystalline because of this universal property.
•A crystalline: substance is one in which the atoms are arranged in a
three-dimensional, regularly repeating, orderly pattern.
•Minerals can be defined as a family
What are atoms and elements?
•Atoms:” smallest electrically neutral assemblies of energy and matter.
•They contain electrons that carry a negative charge and move in the
direction that allow them to neutralize their charge by crowding
around positively charged protons.
•The nucleus contains neutrons which are neutrally charged particles.
•92 naturally occurring atoms, each called an element.
•An element, is defined by the number of protons in its nucleus.
•Electrons in an atom are continuously on the move, spending most of
its time as part of an energy level.
•The stable configuration is to have a completed energy level.
•The first is complete with 2, second and third level are complete with 8
•The bonding of atoms to for minerals takes place when an atom has a
deficit or surplus of electrons in their outer most energy level.
•An electrically charged atom is called an ion.
Ions and Crystalline Structures
•Positively charged ions are called cations (excess positive charge)
•A negatively charged ion is called an anion (excess negative charge)