2 WHAT IS A MINERAL? A MINERAL IS A: SOLID NATURALLY OCCURING (made up of elements)INORGANICCRYSTAL SHAPE (unique to themineral)CHEMICAL COMPOSITION (elements bond together to make a compound)
3 WHAT DOES THAT MEAN? Naturally Occurring = NOT man-made Inorganic = NOT made of/from a living thingCrystal Shape = Repeating pattern of atomsChemical Composition = chemical formulaEx: Quartz has a chemical formula of SiO2
4 NOT A MINERAL? COAL IS NOT A MINERAL, WHY? It is not inorganic because it formed from the remains of living organismsIt does not have a crystal shape
5 NOT A MINERAL? Pearls are organic because they are made from oysters. PEARL IS ALSO NOT A MINERAL, WHY?Pearls are organic because they are made from oysters.They do not have a crystal shape
6 NOT A MINERAL? Glass does not a crystal shape. GLASS IS ALSO NOT A MINERAL, WHY?Glass does not a crystal shape.
7 NOT A MINERAL? 1: It is man-made (not naturally occurring) STEEL IS ALSO NOT A MINERAL, WHY?1: It is man-made (not naturally occurring)2: It does not have a chemical compositionbecause it is a mixture of iron and carbon3: It does not have a crystal shape
8 “Diamonds are Forever” Reading Before you Read:Review the definition of a mineral (SNICC)After you Read:Answer these questions:Can the LifeGem diamonds be considered true minerals? Explain your answer.How are these diamonds different than diamonds mined out of the ground?Would you want to use this company for yourself or for a relative?
9 TWO GROUPS OF MINERALS Nonsilicate Minerals Silicate Minerals Have both Silicon (Si) andOxygen (O) elements in themMake up more than 90% ofEarth’s crustMight have other elements inthem as wellExamples: Quartz (SiO2)Talc Mg3Si4O10(OH)2Do NOT contain Silicon andOxygenDividing into different classesdepending on elements in themExamples: Copper (Cu)Calcite (CaCO3)Galena (PbS)
16 3. LUSTER The way a mineral reflects light Either Metallic or NonmetallicNever described as “shiny” (that is what luster means)
17 METALLIC LUSTERSShines like a metal: Chrome, Silver, Copper, Gold, Bronze, Lead, etc.
18 NONMETALLIC LUSTERS Brilliant (High Shine/Sparkly) Pearly or Silky Glassy(Vitreous)Waxy/GreasyDullEarthy
19 4. STREAKPowdered residue left behind when rubbed across a porcelain tileOnly works for minerals with a hardness less than 7 (tile=7)Streak may be different than outer colorMore consistent/reliable than color
20 5. CLEAVAGE The breaking of a mineral along flat surfaces Can be 1,2, or 3 directional3 Directions: Similar to sides of a cube or rhombusMica breaks into single sheets- 1 Directional
21 6. FRACTURE Breaking of a mineral in an uneven or jagged fashion “Splintery”-splits like wood“Earthy”/Uneven“Conchoidal”-curved“Fibrous”- like fibers
22 7. DENSITY = Mass per volume (g/mL) Every mineral has its own unique density, regardless of its sizeEx: The density of any piece of gold will always be 19 g/mLThe density of any piece of silver will always be 10.5 g/mL