Presentation on theme: "Monday November 02, 2009 Open your notebooks. Write down today’s questions. Today’s Theme: What is a mineral? –What are the ways that minerals can."— Presentation transcript:
Monday November 02, 2009 Open your notebooks. Write down today’s questions. Today’s Theme: What is a mineral? –What are the ways that minerals can be identified? –What defines whether something is a mineral or not? –What is a crystal? –What is the difference between a rock and a mineral? Hand in any late work Progress Reports Tomorrow (Due Thursday) Science Fair Complete Write Up Due Friday!!!!!!!!! OMG
Minerals Today: Use your keen powers of observation to make a list in your notebook of all of the physical properties you notice about the six samples. Think about these questions: –Are they all minerals? –Why do they look the way they do? –How did they form? –What are they composed of? –Where did they come from?
Thursday November 05, 2009 Please write today’s lesson and date written in your notebook. –Today’s lesson: Properties of Minerals What are the physical properties of minerals? How do we tell minerals apart? New Red Books Open to Page 70 Please do not touch equipment yet!!!! Progress Reports Due TODAY (signed by parent) Science Fair Complete Write Up is due Tomorrow.
Properties of Minerals Learning Objectives –What are the ways that minerals can be identified? –What is Moh’s Hardness Scale? –What is the difference between cleavage and fracture? –What are some common uses for minerals?
What is a mineral? A mineral is –Naturally Occurring (made by earth-not man made), –Inorganic (never was alive), –Solid (atoms in fixed position, definite volume/shape), –with a definite crystal structure (repeating pattern of minerals atoms), –and a definite chemical composition (same elements throughout in a certain proportion)
Which of these are minerals? AMBER COAL PEARL SUGAR QUARTZ HALITE MICA
Streak: The color of the powdered form of a mineral when rubbed on an unglazed porcelain plate
Streak The mineral is rubbed on an unglazed porcelain plate to determine the color of the streak powder. Not all minerals have a streak. Any mineral harder than the plate (7+) will leave a scratch instead.
3. Luster Luster describes how light is reflected from a mineral’s surface. A mineral has either –Metallic Luster (shines like a metal) or –Non-Metallic Luster. Dull, earthy, waxy, greasy, pearly, silky or vitreous (glassy)
Luster: The mineral Galena has a metallic luster
Metallic Luster Non-Metallic Luster Examples of Luster
Crystal Systems The way the mineral grows atom by atom makes a shape we call a crystal. –Most of the time you can’t see them. –More time and space it had to grow = bigger crystals
Crystal Forms These are Quartz Crystals These are Quartz Crystals
Texture Texture describes how a mineral feels to the touch. Texture can be described as greasy, soapy, glassy, rough, ragged or smooth. Graphite has a greasy texture.
Cleavage or Fracture Cleavage - When Minerals break along planes (layers) where bonding between atoms is weak. A mineral that splits or breaks easily along smooth, flat surfaces is said to have cleavage. Mica has perfect cleavage in one direction (plane). Halite has cubic cleavage (3 planes).
Three Examples of Perfect Cleavage – Fluorite, Halite & Calcite
Cleavage or Fracture Minerals that break along rough, jagged or uneven edges and surfaces are said to have fracture. –conchoidal (shell-like), splintery, uneven, jagged or earthy Conchoidal Example : Quartz
Don’t be confused between Crystal Faces (sides) and Cleavage Planes! - Both minerals in these pictures show Fracture (not cleavage) These are Quartz Crystals
Special Properties Specific gravity Reaction to acid Striations (lines) Magnetism Fluorescence
Uses of Minerals Gems or Gemstones are highly prized minerals because they are rare and beautiful. An Ore is a mineral that contains a useful substance that can be mined at a profit. Ore NameGives Us HematiteIron ChalcopyriteCopper BauxiteAluminum SphaleriteZinc
Uses of Minerals Gems: Valuable minerals prized for rarity and beauty. Ores: Minerals that can be mined at a profit. Gems: Valuable minerals prized for rarity and beauty. Ores: Minerals that can be mined at a profit.
Uses of Minerals http://www.minsocam.org/MSA/K12/uses/uses.html http://www.minsocam.org/MSA/K12/uses/uses.html http://www.emporia.edu/earthsci/amber/go336/talkingt/ http://www.emporia.edu/earthsci/amber/go336/talkingt/
Birthstones JanuaryGarnet or Rose Quartz FebruaryAmethyst or Onyx MarchAquamarine or Bloodstone AprilDiamond or Quartz Crystal MayEmerald or Crysoprase JuneAlexandrite or Moonstone or Pearl JulyRuby or Carnelian AugustPeridot or Sardonyx SeptemberSapphire or Lapis OctoberOpal or Tourmaline NovemberTopaz or Citrine DecemberTanzanite, Zircon or Turquoise
History of Birthstones In early times, gemstones were believed to possess magical properties. Some minerals were thought to contain a force or hold certain values and powers. Tradition associates a gem with each sign of the zodiac based on a color system. Color was thought to unleash the power attributed to the stone. The Roman, Arabic, Jewish, Polish, Russian and Italian birthstone lists were all different. In time, birthstones became associated with calendar months rather than the zodiac. And people began to select birthstones in colors other than the original. This list of birthstones, which is the one commonly used today, was adopted in 1912 by the American National Association of Jewelers, which later evolved into the Jewelers of America.
Mineral Compositions and Groups Minerals are grouped based on their chemical composition (the elements that make up the minerals). Almost 98% of the Earth’s crust is made of only 8 common elements (O, Si, Al, Fe, Ca, Na, K, Mg).
Silicon (Si) and Oxygen (O) are the most common elements in the Earth’s crust. Major groups are….(In order of size) Silicates (Si, O) (Largest rock forming group) Carbonates (CO 3 ) Oxides (O 3, O 4 ) Sulfides (SO 4 ) Sulfates (SO 3 ) Halides (F, Cl, I, Br) Hydroxides (OH) 2 Phosphates (PO 3 ) Native Elements (Au, Ag, Cu) Mineral Compositions and Groups