EES 1020 1st Edition Lecture 2Intro to Earth Science What are minerals?Mineral: have a crystalline structure (atoms are arranged in a specific repeating order. Occurs in nature. Inorganic. Specific chemical composition.- Minerals that occur in nature are not the same ass mineral supplements that are found in vitaminsRocks: any solid mass of mineral or matter that occurs naturally. Some rocks are made ofone mineral and some are composed of several minerals - Some rocks are non-mineral rocks, like glass volcanic rocks like obsidian.- Coal is a rock but it is made of compacted plant remainsComposition of Minerals:Minerals are made up of the same element placed together in a consistent and repeating pattern. There are 92 naturally occurring elements. Most minerals are a combination of 2 or more elements.Atoms are the smallest part of an element that holds the physical and chemical properties of that elementAtomsStructure of an Atom:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Nucleolus (contains most of the mass of the atom)- Protons (the positive charge of the atom)- Electrons (the negative charge of the atom)- Neutrons (have no charge, balance the atom)Each atom as an atomic number, this number is represented by the number of protons the atom has. The atomic number determines the chemical properties of the element.The mass of an atom can be found by adding the number of protons and neutrons together. Atoms can have different numbers of neutrons without changing the element. When an atom has more or less neutrons than protons it is call an isotope, and it is more unstable of an element.Electronic structure of atoms:There are 3 different shells that hold electrons, the first shell can hold 2 electrons, the second and third can each hold 8 electrons.Chemical Bonding:Occurs when electron shell is weak and atoms lose, gain, or share electrons to bond. Only the outermost electrons can be lost or gained. These electrons are called valance electrons. When they bond ions are formed. If the bond has a positive charge it is called a cation, but if it has a negative charge it is called an anion. \Ionic Bonding:Attraction between oppositely charged ions. Ions are atoms that have lost or gained electrons. This the bonding of cations and anions.Covalent Bonding:Bond where atoms share one or more electrons to form a bond.- Ions pack in different geometric shapes such as tetrahedron, octahedron, cube, and cube octahedron.- The geometric shapes determine the shape of the minerals, and different shapes of minerals helps geologists determine which minerals is which.Polymorphs: minerals that have the same composition, but have different crystalline structures.Largest diamond: 3107 carats (1.37 pounds) it was cut into 105 smaller diamonds, including the Cullinan I and II. These are both part of the British Crown Jewels.Mineral examples: quarts, olivine, fluorite, beryl, native copper, diamond etc. Diagnostic Physical Properties- These are determined by testing and observation, and they are used to determine what type of mineral the substance is.Crystal form: Shape that the element naturally grows in (geometric shape). Crystalline structure can be disrupted because of lack of spaceColor: way the mineral looks in light, can be expressed with words like transparent, translucent, opaque, red, blue, brown, etc. Luster: shine or lack of shine a mineral has. Words like metallic, silky, greasy, etc can be used to describe lusterStreak:the color of the mineral in dust form, to test this a porcelain plate is used. Variety of colors are expressed. Can be different from mineral color.Cleavage/fracture: how minerals respond to pressure. A mineral that has poor cleavage is likely to break off randomly in chunks, whereas a mineral with good cleavage will break off into more thin, flat pieces consistently. Cleavage can be described by geometric planes, the more planes the poorer the cleavage.Hardness: how well the mineral resists to scratches, hardness is tested with the mohs hardness scale.Secondary Properties that apply to some minerals:- Reaction to hydrochloric acid- Double refraction- Magnetism (attracted to magnets)- Taste (salty)- Fluorescence (glows under black light)- Smell- ElasticityAsbestos: a variety of silicate minerals that break apart into thin strong fibersDiamond or Cubic Zirconia?Diamond:- Hardness of 10 (the hardest mineral)- Natural and can contain flaws and inclusions- Considered to possess brilliance, it shines with flashes of bright white- Has a high thermal conductivity Cubic Zirconia- Hardness of 8.5- Synthetic and flawless - Has flashes that have color to them- Is a thermal insulator Mineral Groups:- There are about 3800 known minerals - There are only 8 minerals that make up earth’s crust: oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium. Oxygen and silicon make up 75% of the earth’s crustThe Silicates:- The most important mineral group. Most rock-forming minerals. - There are dark silicates- ferromagnesian (Mg, Fe)- There are light silicates- non-ferromagnesian (Ca, Na,