Minerals Mineral Characteristics 1. occurring 2. 3. 4. structure 5. Definite composition Naturally Mineral Characteristics 1. occurring Inorganic 2. Solid 3. Crystalline 4. structure chemical 5. Definite composition Naturally Occurring Geologists have discovered over minerals However, only about are considered as common minerals. All minerals are naturally made (not man made ) of elements that are found in crust. 100 3,000 Earth's elements The two most abundant are?? and. Naturally Occurring Geologists have discovered over minerals However, only about are considered as common minerals. All minerals are naturally made (not man made ) of elements that are found in crust. The two most abundant are Oxygen 100 3,000 Earth's elements Silicon and. 1
Naturally Occurring crystallization Minerals are formed by the solution of materials once dissolved in a. 90% of all minerals are classified as silicates (contain oxygen and silicon) other mineral families: carbonates, phosphates, oxides Crystallization occurs as the solution either cools or evaporates (these minerals are called evaporites) The slower the process, the the crystals. Naturally Occurring Minerals are formed by the of materials once dissolved in a. Crystallization occurs as the solution either cools or evaporates crystallization solution LARGER The slower the process, the the crystals. NOT Inorganic Minerals are made of materials that were once living part of a thing. Graphite Example: is made of carbon that NOT was part of any thing. Coal Nonexample: is made of carbon that was plants once part of that millions of years ago. living lived Solid Minerals have a definite and. atoms The that make up minerals are packed tightly shape very together. fixed They maintain a position. volume 2
Crystals are made up of (or particles) that are arranged atoms in a pattern. Properties of a mineral, such as and hardness repeating shape crystal, are determined by its arrangement atoms structure (or the of its ). Most common crystal structures: 1. Cubic 2. Rhombohedral Most common crystal structures: 3. Hexagonal Halite Calcite 4. Tetrahedral some quartz Diamond 3
Most common crystal structures: 5. Sheet Mica Example of different arrangements of the same atoms: Definite Chemical Composition Minerals always contain the elements in a definite proportion. same These elements and their proportions determine the and properties of a mineral. These properties help to determine the best for the mineral. Definite Chemical Composition Minerals always contain the elements in a definite proportion. These elements and their proportions determine the physical and properties of a mineral. These properties help to determine the best uses for the mineral. same chemical 4
NOTES Minerals.notebook properties are also important in its A mineral s identification. Color Luster Easiest property to observe reflect light. The ability of a mineral s surface to reliable property for identification Least Classified as either: or Metallic Nonmetallic Luster Streak Metallic : Shiny appearance ("metal looking") Nonmetallic Dull, glassy, or waxy : (may look somewhat shiny, but not like a piece of metal) powder form. The color of a mineral in Observed by rubbing a mineral against a piece of plate streak. unglazed tile called a 5
NOTES Minerals.notebook Fracture and Cleavage (different forms of "breakage") Fracture and Cleavage break apart can help to The way a mineral can identify it. All depends on the internal arrangement of the. atoms irregular way. Fracture: Breaks apart in an Most fractures are rough however, some are a smooth shell shaped fracture or a smooth recessed fracture known as a conchoidal (con-coy-dal) fracture. Fracture and Cleavage Breaks easily along FLAT Cleavage: surfaces. Recognized by the appearance of very flat shelf-like surfaces after breakage. May 5 6:48 AM 6
NOTES Minerals.notebook Examples: Examples: Mica cleaves in one direction (looks like sheets) Potassium feldspar cleaves in two directions 90 degrees apart (looks like stair steps) Examples: Halite cleaves in three directions (looks like a cube) May 5 6:43 AM not "shelf-like" VS. "shelf-like" May 5 7:09 AM Apr 27 7:33 AM 7
NOTES Minerals.notebook Density volume Mass per unit Density = Mass determined using a scale Graduated Cylinder Volume determined using displacement Overflow Can & Bucket Apr 24 6:30 PM 19 g/cm3 5 g/cm3 Hardness resistance a mineral offers against A measure of being scratched (not broken). scratch Ratings determined by using a mineral to some common objects that have been assigned hardness values. Rated on a scale from 1 to 10 known as Mohs Hardness Scale. Hardness of Some Common Items Fingernail (2) Penny (3) Nail (4.5) Glass (5.5) Streak Plate (7) Diamond (10) scratch the item, it is If a mineral can than that item. softer (or) harder 8
Ratings determined by using a mineral to scratch some common objects that have been assigned hardness values. Hardness of Some Common Items Fingernail (2) Glass (5.5) Penny (3) Streak Plate (7) Nail (4.5) Diamond (10) If a mineral can the item, it is harder scratch than that item. If a mineral can scratch a fingernail, but not a penny...what is its hardness? Friedrich Mohs (Austrian mineralogist) 1812: Mohs Hardness Scale Mohs Hardness Scale 1 Talc 6 Feldspar 2 Gypsum 7 Quartz 3 Calcite 8 Topaz 4 Fluorite 9 Corundum 5 Apatite 10 Diamond If a mineral can another mineral, it is harder scratch than that mineral. Will calcite leave a scratch on quartz? Special Properties Fluorescence: the ability to under ultraviolet glow light. Special Properties Magnetism Special Properties Reaction to acid Double image 'bubbles' with acid 9