2.  Occurs naturally  Is a solid  Has a definite chemical composition  Has atoms arranged in an ordinary pattern (crystal structure)  Is inorganic (not alive)

3.  Made of 2 or more elements  Example:  Quarts: silicon & oxygen  Halite: sodium & chlorine  Galena: lead & sulfur

4.  Minerals with only one element are called Native Minerals (native element)  Examples:  Gold  Silver  Copper  Sulfur  Diamonds (carbon)

5. 1.Magma  Atoms move freely in liquid magma  As magma cools & hardens atoms come closer together to form solid mineral  Depending on the atoms different minerals can form from the same magma mass  Rate of cooling determines the minerals grain size

6. 2.Evaporation  Water containing dissolved ions evaporates  Ions come together to form a mineral 3. Metamorphic minerals yMinerals can also be changed into other minerals yThey recrystallize due to changes in  Heat  Pressure  Chemical action of water

7.  All minerals are crystalline: atoms arranged in a regular pattern  A crystal is a regular geometric solid with smooth surfaces called crystal faces.  Arrangement of ions (atoms with a positive or negative charge) determines the shape of the crystal  The angle at which crystal faces meet is always the same for each kind of mineral (can use to identify)

8.  Cubic  Orthorhombic  Tetragonal  Triclinic  Hexagonal  Monoclinic  If you can’t see a crystal shape (face) it is because space is too limited, atoms of 1 crystal join to another & faces (shapes) are lost

9. A. Silicates  Made from silica tetrahedrons 1. Quartz  Second most abundant mineral in Earth’s crust 2. Feldspar  60% of the crust, framework silicate  Divided into 2 groups  Potassium feldspar: most common orthoclase  Sodium-Calcite feldspar: plagioclase  Example: Albite & Oligoclase

10. 3. Mica  Very soft, sheet silicate  White mica (muscovite)  Dark Mica, black or brown (biotite) 4. Talc  The softest mineral 5. Amphiboles  Most common is hornblende, which is a ferromagnesium silicate  Can belong to almost any silicate family 6. Pyroxenes  Most common is augite  Also ferromagnesium silicate

11. 7. Olivine  Single silica tetrahedron 8. Garnets  Very hard 9. Kaolinite or Kaolin  Formed by weathering of feldspar and other silicate minerals

12.  Isolated tetrahedra: silicon-oxygen tetrahedra that are linked only by atoms of elements other than silicon and oxygen (1 Si & 4 O)  Ring Silicates: tetrahedra are joined into 3, 4, or 6 sided rings by shared oxygen atoms  Single-chain silicates – each tetrahedron is bonded to 2 others by shared oxygen atoms  Double-Chain Silicates: 2 single chains of tetrahedra bonded (linked) to each other

13.  Made of one carbon atom combined with three oxygen atoms 1. Calcite (Calcium)  Most common  Colorless calcite is iceland spar (ice-like) 2. Dolomite (magnesium)  Coarse or fine grains  Doesn’t react as much to acid test as calcite 3. Malchite and azurite (copper) 4. Siderite (iron)

14. 1. Hematite  Most common iron oxide  Leaves red-brown streak 2. Magnetite  Black magnetic iron oxide  Example: Lodestone 3. Pyrite  Most common iron sulfide

15.  1. Shape of its crystals  Ex: Halite (table salt) crystals are isometric  no matter how large or small they have to be the same shape Test: look under dissecting microscope

16.  2. Colors  Some minerals have more than one color  Impurities in a mineral can change its color  Ex: Quartz- clear, with iron-purple, with titanium-pink  Exposure to air changes colors  Ex: Brass is yellow-air is bronze  Bronze is brown – air is purple  Test: simple look at it

17.  3. Luster – the way a mineral reflects light  Two types  1. Metallic: looks like metal  2. Nonmetallic: does not look like metal  Ex: glassy, earthy, pearly etc.  Test: look at the mineral, ask yourself ‘does it look like a piece of metal’ If it does than it is metallic if not then nonmetallic

18.  The way a mineral shines in a light metallicnonmetallic  Either metallic or nonmetallic

24.  4. Cleavage  Most minerals break in a particular pattern 1. Cleavage  If breaks along flat surfaces it forms a sheet  If breaks in three directions that are at right angles 2. Fracture:  if a mineral breaks in more than one direction  If a mineral breaks on a curved surface (conchoidal fracture) Test: look at sides and compare to examples. If it is flat then cleavage, if not then fracture

25. y“Sheety” Cleavage Fluorite cleaves at right angles

26. yConchoidal or shell-like fracture yFibrous facture

27. yCLEAVAGE yFRACTURE yin

28.  5. Hardness  Depends on the arrangement of its atoms and the strength of the bond  The harder mineral will always scratch the softer one  Moh’s scale: shows hardness of minerals  The higher the number the harder the mineral Test: use hard points to gently wipe across the mineral. Each point is worhta certain number, as soon as the point scratches the mineral you stop. That is the number

29.  6. Streak: indicator of true color  Streak is the same for all samples of the same mineral  Hard minerals leave no streaks Test: scratch the mineral on an unpolished porcelain tile. The powder left behind is the true color

31.  7. Specific Gravity (Heft): ratio of the weight of a mineral to the weight of an equal volume of water  Specific gravity is always greater than 1  Nonmetallic- less than 3  Metallic – about 5  Gold if pure – 19.3 Archimede’s principle – loss of weight is equal to the weight of the displace water

32.  Formulas: Specific Gravity = weight of sample in air weight of equal volume of water or = weight of sample in air loss of weight in water

33.  Example: A mineral weighs 50 Newtons in air and 30 Newtons in water Specific Gravity = 50 N (50 N – 30 N) = 50 N 20 N = 2.5 So, the mineral is 2.5 times as heavy as an equal volume of water

34. Test:  Use a Newton scale and attach a mineral to the scale.  Then find the weight in air and then place mineral in water (without touching side) to find weight in the water.  Finally use the specific gravity formula

35. 8. Acid Test: to find if a mineral is a carbonate  Place a small drop of weak hydrochloric acid on a mineral.  If mineral bubbles it has carbon, if not it doesn’t 9. Special Properties of Minerals: Magnetic: use a magnet and see if it sticks Taste: certain minerals have a specific taste *never taste a mineral without being told to Fluorescence: glowing while under a U.V. light Phophorescent: continues to glow after the U.V is off Radioactive: test minerals with a Geiger counter Double Refraction: splits light rays into two parts (will see a double image) look through mineral for image