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  1. • This term is used in several different ways. • Health and fitness – extol the benefits of it together with vitamins. • Mining Industry – for anything taken out of the ground (such as coal, iron core or sand and gravel). • Geologist – any naturally occuring inorganic solid that possesses an orderly crystalline structure and a well defined chemical composition.
  2. • Naturally occurring – It means that a mineral should be formed by natural geologic processes. – This is why synthetic diamonds and rubies, as well as variety of other usefuk materials produced by chemist are not considered as minerals
  3. • Solid – In order for something to be considered as mineral, it should be solid at temperatures normally experienced at Earth’s surface. – Thus, Ice (Frozen water) is considered as mineral whereas liquid water is not.
  4. • Orderly Crystalline Structure – Minerals are crystalline substances which means their atoms are arranged in an orderly, repetitive manner.
  5. • This orderly packing of atoms is reflected in the regularly shaped objects we call crystals. • Some Naturally occurring solids, such as volcanic glass (obsidian), lack a repetitive atomic structure and are referred to as amorphous (without form) and are CONSIDERED AS MINERALS.
  6. • Well-defined Chemical Composition – Most minerals are chemical compounds made up of two/more elements. A few (such as Gold and Silver) consist of only a single element. • The common mineral quartz consist of 2 oxygen (O) atoms for every Silicon (Si) atoms, giving it a chemical composition expressed by the formula SiO2. Thus, no matter what the environment is, whenever atoms of Oxygen and Silicon joined together in the rato of 2 to 1, the product is always quartz.
  7. • Generally Inorganic Inorganic – Substances such as stone and metal that do not come from living things. • Minerals are generally inorganic. Inorganic crystalline solids, as exemplified by ordinary table salt (Halite) that are found naturally are considered minerals. • Organic Compounds on the other hand, are generally not. • Ex. Sugar – (Crystalline like salt) comes from sugarcane or sugar beets and is common example of such an organic compound.
  8. • Minerals and other earth materials are composed of chemical elements. • Elements – Fundamental component of matter that cannot be broken into a simpler particles by ordinary chemical processess. (Most common minerals consist of a small number – usually 2 to 5 of different chemical elements).
  9. Oxygen • Silicon • Aluminum • Iron • Calcium • Sodium • Potassium • Magnesium
  10. • In nature, most chemical elements have either a positive (+) or negative (-) charge. – ION- atom with either positive/negative charge – CATION – Positively charged atom – ANION – Negatively charged atom
  11. • Most minerals are made up of 2-5 essential elements. Ex. Formula of quartz is SiO2. One atom of Silicon for every 2 atoms of oxygen.
  12. • The mineral has a crystalline structure, and therefore every mineral is a crystal. – Crystal – any solid element/compound whose atoms are arranged in a regular, periodically repeated manner
  13. Ex. Mineral halite (common table salt)
  14. • NaCl – One sodium for every one chlorine (You can see here that the sodium & chlorine ions alternate in orderly rows & columns intersecting at right angles. Figure 1.1 is the crystalline structure of halite). Figure 1.1
  15. • Crystalline Structure - orderly, repetitive arrangement of atoms in a crystal.
  16. As evaporation continues, more and more sodium & chlorine ions would precipitate onto the faces of the growing crystal.
  17. • Crystal Face – flat surface that develops if a crystal grows freely in an uncrowded environment. Under perfect conditions, the crystal that forms will be symmetrical. – Symmetrical – has a corresponding similar parts: in other words, one side is the same as the other.
  18. • This properties allow geologists to identify a mineral in the field. – Chemical composition – Crystal structure • But if you pick a crystal of a mineral( for example, halite), you cannot see the atoms. You should measure its chemical composition and crystal structure by laboratory procedures, but such analyses are expensive & time consuming. • Geologists commonly use properties to identify minerals.
  19. • Crystal Habit – characteristic shape of an individual crystal & the manner in w/c aggregates of crystals grow. Geologists can identify that this mineral is a prismatic quartz because of its elongated shape.
  20. • Cleavage – tendency of some minerals to break along that surface, which are planes of weak bonds in the crystal. When a mineral has excellent cleavage, sheet after sheet can be peeled from the crystal, like peeling layers from an onion.
  21. • Fracture – a manner n which minerals break other than along planes of cleavage. The type of fracture shown in this picture is concoid.
  22. • Hardness – resistance of a mineral to scratching & is one of the most commonly used properties for identifying a mineral.
  23. • Mohs Hardness Scale – after Friedrich Mohs, he developed this scale in the early 19th century.
  24. This scale was used to measure the hardness of a mineral more accurately.
  25. Mineral Hardness scale 1-10: • Toronto Girls Can Flirt And Only Quit To Chase Dwarves . • Terrible Giants Can Find Alligators Or Quaint Trolls Conveniently Digestible • Tall Girls Can Flirt And Other Queer Things Can Do! • The Girls Can Flirt And Other Queer Things Castrate Donkeys!
  26. • Color – most obvious property of a mineral is often used in identification. But color can be unreliable because small amount of chemical impurities can dramatically alter color.
  27. • Streak – refers to the color of the fine powder of a mineral. It is observed by rubbing the mineral across a piece of unglazed porcelain known as the “streak plate”.
  28. • Streak • Streak Plate
  29. • Luster – manner in which a mineral reflects light. A mineral with a metallic look irrespective of color has a metallic luster. As a result, it looks like gold & is commonly called “fool’s gold”.
  30. Pyrite Mineral
  31. •Metallic - Minerals with a metallic luster are opaque and reflective, like metal. The metallic elements, most sulfides, and some oxides belong in this category. •Opaque-
  32. • chalcopyrite500
  33. • Pearly - Describes a luster similar to the inside of a mollusk shell or shirt button.
  34. • Earthy- This luster defines minerals with poor reflective qualities, much like unglazed porcelain. Most minerals with a dull luster have a rough or porous surface. • Porous- Containing rounded, tiny holes throughout. Porous minerals are lightweight and easily dyed.
  35. • Resinous - This is the luster of many yellow, dark orange, or brown minerals with moderately high refractive indices - honey like, but not necessarily the same color. • Refractive indices- The amount of refraction that takes place in a particular substance, which is a direct connection to the speed of light in that substance.
  36. • Reaction to acid • Magnetism • Radioactivity
  37. • Fluorescence - FluorescenceProperty exhibited in certain minerals in which they display a glowing effect when having ample illumination with ultraviolet light.
  38. • Phosphorescence- Phosphorescence • The ability of some fluorescent minerals to keep on glowing for several seconds after the fluorescent lamp has been removed. • these properties can be characteristics of specific minerals
  39. • Geologists classify according to their chemical elements. • Silicates, together w/ oxygen make up about 42% of earth’s crust. They are abundant for 2 reasons. First, silicon & oxygen are the two most plentiful elements in the crust. Secondly, silicon & oxygen combine readily.
  40. • Carbonate minerals are much less common than silicates n earth’s crust, but they are important rock-forming minerals because they form sedimentary rocks that cover large regions of every continent. The shells & other hard parts of the most marine organisms such as clams, oysters & corals are made of carbonate materials.
  41. • Commercially Important Minerals are minerals from which metals / other elements can be profitably recovered. • Industrial minerals - rocks/ minerals that have economic value exclusive of metal ones, fuels & gems.
  42. • Gem – mineral that is priced primarily for its rarity and beauty although some gems such as diamonds are also used industrially. • Precious Gems- Any of several gems, including the diamond, emerald, ruby, and sapphire, that have high economic value because of their rarity or appearance.