Review of Sc.10 and Chapter 5 Earth Science 11 Heath Text

Ghost Notes: Fill in the blanks on your ghost notes

Review ( Chapter 3 and Science 8/9/10 )  Matter is anything that has mass and volume.  All matter is composed of elements  An element is a substance that cannot be broken into simpler substances by ordinary chemical means. Periodic Table!!!

 An atom is the smallest particle of an element that has all the properties of that element. Each atom has a nucleus that contains protons (positively charged), and neutrons (no charge). The moving charged particles are called electrons and they orbit the nucleus.  Isotopes are atoms of the same chemical element with different mass numbers (different numbers of neutrons).

 Compounds are substances that contain two or more elements chemically combined.  Compounds are formed when atoms bond  Ionic bond: the bond that forms as a result of the attraction between positively and negatively charged ions; a transfer of electrons, (Metal + Non-Metal)  Covalent bond: The bond formed from the sharing of electrons by atoms, (Non-Metal+ Non-Metal)  Metallic bond: atoms become positively charged ions, sea of electrons

What is a mineral?  In order for a material to be called a mineral several things must be true:  Occurs naturally  Is a solid  Has a definite chemical composition (elements combined in definite proportions  Has its atoms arranged in an orderly pattern  Is inorganic (not formed by any process involving plants, animals, or other organisms.)  Water is not a mineral because it is not solid.  Window glass is not a mineral because it does not occur naturally.  A pearl is not a mineral because it is formed by an oyster.  Coal is not a mineral because it is made from plant remains, it lacks a definite composition, and its atoms are not arranged in an orderly way.

 Minerals may be elements or compounds  The two most abundant elements are oxygen and silicon = These are found in more than 90% of the minerals in the crust.  The eight most common elements in the Earth’s crust are: Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium.  Most minerals are compounds. For example Quartz is a compound of silicon and oxygen.  A few minerals are composed of single elements called native minerals, or native elements. = Gold, Silver, Copper, Sulfur, and Diamond.  Minerals can form in several ways:  Many form out of molten earth material or magma.  Some form when water containing dissolved ions evaporate. (Halite forms when salt water evaporates.)  Minerals can be changed into different minerals by heat, pressure, or the chemical action of water.

Structure of Minerals:  All minerals are crystalline. Their atoms are arranged in a particular pattern.  Minerals are often found as crystals: a regular geometric solid with smooth surfaces called crystal faces.  The angle at which crystal faces meet is always the same for each kind of mineral and is helpful for identification purposes.  Only 6 basic crystal shapes occur: cubic system, orthorhombic system, tetragonal system, triclinic system, hexagonal system, monoclinic system (pg. 99 of textbook).  Not all crystalline substances have crystal faces. Inadequate space to grow.  More than 90 % of the minerals in Earth’s crust are members of the silicates. (Compounds of the elements silicon and oxygen + one or more metallic elements.)  The basic unit (four oxygen atoms packed around a silicon atom) is held together by covalent bonds between the silicon atom and oxygen atoms. This makes a geometric figure called a tetrahedron.  Silicate minerals are built around the silica tetrahedron.  The crystal shape, hardness, cleavage, and density of a mineral are determined by the internal arrangement of its atoms or ions.

Chapter Five.2 Please take notes on the following information…

Identifying Minerals:  Over 2000 minerals are known. There are common minerals (quartz, feldspar, mica, calcite…) and rare (gold, diamond) minerals  Common minerals that make up the majority of the Earth’s crust are called rock-forming minerals.  Most rock forming minerals are silicate minerals.  Minerals are identified by their physical properties.  The study of minerals and their properties is called mineralogy

Identification by Inspection and Tests:  Colour: Obvious but not very useful  Luster: The way it shines in reflected light. Metallic or Nonmetallic, pearly, earthy, vitreous (like glass)  Crystal Shape: Only helpful if they have had time and room to form giving their atoms or ions (an atom or group of atoms in a negative or positive charged condition) time to arrange themselves in patterns.  Streak: colour of the mineral when it is finely powdered  Cleavage: breakage along smooth planes. This depends upon zones of weakness in the crystal structure.  Hardness: Mohls’ scale. Resistance to being scratched.  Fracture: the broken surface is irregular and not in a flat plane.  Specific gravity: the ratio of the weight of a mineral to the weight of an equal volume of water.  The acid test: Hydrochloric acid

Special Properties of Minerals:  Magnetic: Magnetite-an iron ore, Lodestone  Taste: Halite=Rock Salt  Fluorescence: fluorite, calcite (glow under UV)  Phosphorescent: (glows after UV exposure) willemite and sphalerite  Radioactive: uranium (harmful)  Double refraction: (splitting the light ray into two parts.) Iceland Spar – a type of Calcite

Silicates: From Silica Tetrahedrons  Silica tetrahedron = nature’s most important building block for minerals.  Quartz: hardest (7) of the common minerals, glassy or greasy luster, fracture is shell-like or irregular, colour varies. It is the second most abundant mineral in Earth’s crust. (Important part of granite)  Feldspar: the most abundant family of minerals in Earth’s crust. (60%)  Feldspar’s have three major properties: two directions of cleavage, a hardness of 6, and a pearly luster.  Two major groups of Feldspars: potassium feldspars and sodium calcite feldspars. (based upon the ionic structure)  Potassium Feldspar: Orthoclase  Sodium-calcite feldspars are called plagioclase feldspars: Albite and oligoclase.

Silica Tetrahedrons continued….  Mica: soft silicates  Talc: softest mineral #1 on Mohls’ scale  Amphiboles are a family of complex silicate minerals = Hornblende long needle-like crystals  Hornblende is also a Ferromagnesian silicate  Ferromagnesian silicates all contain atoms of iron and magnesium AND they are always dark in colour.  Pyroxenes: Augite (Awjyte) is the most common member of this family. (Cleavage surfaces meet nearly at right angles.) (shorter, stouter crystals)  Olivine, Garnets, and Kaolinite “oh my”…page 55

Non-Silicates:  Carbonate group: made of one carbon atom combined with three oxygen atoms and has a negative charge of two.  A carbonate mineral = carbonate groups joined with various metal ions. (limestone and marble)  Most common = Calcite (ACID TEST)  Colourless transparent calcite is called Iceland spar = properties of double refraction  Dolomite is calcium magnesium carbonate  Copper carbonates = malachite (green) and azurite (blue)  Iron carbonate = siderite (brown or yellow-brown)

Iron Oxides and Sulfides:  Minerals that contain large amounts of the metal element iron.  ECONOMICALLY IMPORTANT…(will be discussed later)  Iron tends to be combined with either oxygen or sulfur to form an oxide or sulfide.  Oxide: a mineral consisting of a metal element combined with oxygen.  Sulfide: a metal element combined with sulfur.  Each iron-bearing mineral has its own identifying properties.  Hematite: most common. ALL leave a red-brown streak on the streak plate.  Magnetite: attracted to a magnet. Lodestone is a highly magnetic variety of magnetite…natural magnet.  Pyrite: iron sulfide…fool’s gold

mplete)#mediaviewer/File:Dioptase jpg Dioptase: Image by Rob Lavinsky

Hornblende: this is a sample from the Smithsonian Museum of Natural History.

Feldspar: The most abundant family of minerals in the Earth’s crust

Pure Quartz istory_Museum.jpg

Muscovite from Mitchell County North Carolina

Garnet: These share a common crystal structure. erals/garnet.shtml

Calcite: Carbonate

Azurite and malachite from Morenci, Arizona: a deep blue copper carbonate.

Pyrite with hematite from Rio Marina, Isle of Elba, Italy Fool’s Gold

Fluorite in normal light and under short wave ultraviolet light minerals/\

Fluorescent rocks and minerals

Dolomite crystals from Penfeld, New York

Cinnabar: a toxic mercury sulfide mineral

The End… Homework Complete “5.2 Section Review” on page 102 of your textbook Coming up… Section 5.3 Identifying Minerals & Lab