Minerals Building Blocks of Rocks Chapter 5 Minerals
Minerals: Building Blocks of Rocks ~Chapter 5~ ^_^
Minerals: the building blocks of rocks v. Definition of a mineral • Natural • Inorganic • Solid • Possess an orderly internal structure of atoms • Have a definite chemical composition
Composition and structure of minerals v. Atoms • Smallest particles of matter • Elements • Basic building blocks of minerals • Over 100 are known
Periodic table of the Elements
How atoms are constructed v. Nucleus – central part of an atom that contains • Protons – positive electrical charges • Neutrons – neutral electrical charges • Have all the characteristics of an elements v. Energy levels, or shells • Surround nucleus • Contain electrons – negative electrical charges
Simplified view of the atom
How atoms are constructed v. Atomic number is the number of protons in an atom's nucleus v. Bonding of atoms • Forms a compound with two or more elements • Ions are atoms that gain or lose electrons v. Isotopes • Have varying number of neutrons
How atoms are constructed v. Isotopes • Have different mass numbers – the sum of the neutrons plus protons • Many isotopes are radioactive and emit energy and particles
Minerals v Physical properties of minerals s s s s Crystal form Luster Color Streak Hardness Cleavage Fracture Other properties (taste, smell, elasticity, malleability, feel, magnetism, double refraction)
Crystal Form
Luster
Cleavage
Streak
Hardness
Cleavage
Fracture
Other Properties. Crystal Form
The mineral quartz often exhibits good crystal form
Pyrite (fool’s gold) displays metallic luster
Three examples of perfect cleavage – fluorite, halite, and calcite
Conchoidal fracture
Minerals v. Physical properties of minerals • Other properties • Feel • Magnetism • Double Refraction • Reaction to hydrochloric acid
Minerals v A few dozen minerals are called the rockforming minerals • The eight elements that compose most rockforming minerals are oxygen (O), silicon (Si), aluminum (Al), iron (Fe), calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg) • Most abundant atoms in Earth's crust: • Oxygen (46. 6% by weight) • S ilicon (27. 7% by weight)
Minerals v. Major Mineral groups • Rock-forming silicates • Most common mineral group • Contain the silicon-oxygen tetrahedron • Four oxygen atoms surrounding a much smaller silicon atom • Feldspars are the most plentiful mineral group • Crystallize from molten material
Minerals v. Mineral groups • Rock-forming silicates : • Olivine – independent tetrahedra • Pyroxene group – tetrahedra are arranged in chains • Amphibole group – tetrahedra are arranged in double chains
Hornblende – a member of the amphibole group
Minerals v. Mineral groups • Rock-forming silicates • Micas – tetrahedra are arranged in sheets Biotite and Muscovite • Feldspars - Blocky • Two types- Orthoclase and Plagioclase • Quartz –
Potassium feldspar
Plagioclase feldspar
Major Mineral groups: v. Nonsilicate Mineral Groups: v. Oxides v. Sulfides v. Carbonates • A major rock-forming group • Found in the rocks limestone and marble • Evaporites • Halite and gypsum are found in sedimentary rocks • Many have economic value
Native Copper
Some common non-silicate minerals
Mineral resources • Reserves are already identified deposits • Ores are useful metallic minerals that can be mined at a profit • Economic factors may change and influence a resource
An underground halite (salt) mine
The Bingham copper mine in Utah
Formative Mineral Quiz Directions: s. Take out separate piece of paper and number 1 -17 s. For each slide, identify the mineral either based on how it looks or on the clue given. s. Correct quiz and record which ones you need study more!
Concoidal Fracture
IDENTIFY IT!
HCL Test (fizzing)
Double Refraction
IDENTIFY IT!
Perfect Cleavage (3 at 90 deg. )- NO THER HINTS!
Definitely not gold… unless you’re a fool.
Fibrous
MOHS = 1
Streak Test
Magnetic… but the streak is throwing me off
Uber Magnetic
Filmy… Flat… White…
Black starts with B.
Metallic mineral. Ugly color.
Looks like Pyrite… but its not
Speckled. Reacts with Acid when powdered
Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. Quartz (Box 1) Olivine ( Box 1) Calcite (Box 1) Azurite ( Box 2) Halite (Box 3) Pyrite ( Box 2) Gypsum ( Box 1 OR 3) Talc ( Box 3) Hematite ( Box 2) Magnetite ( Box 2) Muscovite ( Box 1) Biotite ( Box 1) Limonite ( Box 2) Chalcopyrite ( Box 2) Dolomite ( Box 3)
- Slides: 56