Identifying Minerals How could you identify what these minerals are? Properties of Minerals (pgs )Jobs: Reader- reads section out loud Reader- reads section out loud Scribe- group creates a multiple choice question for the reading, scribe writes it down (with answer) Scribe- group creates a multiple choice question for the reading, scribe writes it down (with answer) Teacher- teaches section to class Teacher- teaches section to class Scribe 2- group creates a true/false question, scribe 2 writes it down (with answer) Scribe 2- group creates a true/false question, scribe 2 writes it down (with answer) 1.Color (pg. 70) 2.Luster (pg. 70) 3.Streak (pg. 71) 4.Cleavage and fracture (pg. 71) 5.Hardness (pg. 72) 6.Density (pg. 72) 7.Special properties (pg. 73) Color Same mineral can come in a variety of colors Rose quartz, milky quartzboth quartz! Color is NOT a good way to identify minerals Impurities, air, water can change the color Luster Definition: The way a mineral reflects light Different words used to describe luster Streak Definition: The color of a mineral in its powdered form (rub on streak plate) Streak color not always the same as mineral color All minerals of the same kind, even if they are different colors, will streak the same color Black and brown hematite will both streak brown Cleavage and Fracture Cleavage: the splitting of a mineral along smooth, flat surfaces Fracture: the tendency of minerals to break unevenly along curved or irregular surfaces Hardness Definition: a minerals resistance to being scratched Use Mohs Hardness Scale 1= softest; talc is the example on Mohs scale 10= hardest; diamond is Mohs example Density/Specific Gravity Definition: the measure of how much matter is in a given amount of space Measured in g/cm 3 Specific gravity: comparing the minerals density to the density of water Special Properties Fluorescence Magnetism Chemical reaction- carbonates fizz Taste Optical properties Radioactivity