How to identify a mineral

How to Identify a Mineral Mineral Identification • We identify minerals so we can recognize valuable resources (useful or beautiful) Mineral Identification • There are tests performed on minerals so they can be identified Test Test • Mineral Appearance: Color and appearance are two clues used to identify minerals Azurite can always be identified by its striking blue color Test • However, this test is not enough to identify most minerals Which one is gold and which one is iron pyrite (fool’s gold)? Test Test • Hardness: the measure of how easily a mineral can be scratched Talc can be scratched by a fingernail, diamonds cannot be scratched by anything but another diamond http://www.cnn.com/2012/08/09/living/olympians-bite-medals/index.html Test • Hardness is measured using a Mohs scale Test Test • Cleavage or Fracture: how a mineral breaks Test • Cleavage: the physical property of some minerals that allows them to break along smooth, flat surfaces Mica always cleaves in thin, flat sheets Halite cleaves at 90 degree angles Test • Fracture: the physical property of some minerals that causes them to break with uneven, rough, or jagged surfaces Test Test • Other properties: some minerals have unique properties that allow them to be easily identified Magnetite will pick up iron like a magnet Test Calcite can cause double images Test These minerals “glow” in the mining tunnel when under uv light Willemite and Calcite have a property known as fluorescence, they will “glow” under uv light Summary There are tests to determine the identity of a mineral Color and appearance Hardness Luster Specific Gravity Streak Cleavage and Fracture Other Properties http://www.youtube.com/watch?v=c7wJP_K_sAQ&feature=related http://abcnews.go.com/US/oklahoma-teenager-finds-385-carat-canary-diamond/story?id=20633996 Review What are the tests? Color and appearance Hardness Luster Specific Gravity Streak Cleavage and Fracture Other Properties Review Why we sometimes need to more than one test? It may be difficult to identify a mineral based on only one characteristic It may share common features with other minerals Review Which test uses the Mohs scale? Hardness Review What type of luster each of the following minerals have? (Metallic or Non-metallic) Metallic, non-metallic, non-metallic, metallic Review What type of breakage these minerals show? Cleavage, fracture, fracture Review Which test is being performed here? Streak Test [...]... Streak: the color a mineral leaves on a porcelain tile Hematite (on left) looks gray, but leaves a reddish-brown streak Iron pyrite (on right) is gold colored, but leaves a greenish-black streak Test 6 Test 6 • Cleavage or Fracture: how a mineral breaks Test 6 • Cleavage: the physical property of some minerals that allows them to break along smooth, flat surfaces Mica always cleaves in thin, flat... Willemite and Calcite have a property known as fluorescence, they will “glow” under uv light Summary There are 7 tests to determine the identity of a mineral 1 Color and appearance 2 Hardness 3 Luster 4 Specific Gravity 5 Streak 6 Cleavage and Fracture 7 Other Properties http://www.youtube.com/watch?v=c7wJP_K_sAQ&feature=related http://abcnews.go.com/US/oklahoma-teenager-finds-385-carat-canary-diamond/story?id=20633996... Luster: the way a mineral reflects light Test 3 • A mineral can be metallic or non-metallic, such as glassy, dull, pearly, or silky Non-metallic, dull Non-metallic, glassy Metallic Test 4 Test 4 • Specific Gravity: a mineral s weight is compared to the weight of an equal sized amount (volume) of water Gold has a specific gravity of 19, iron pyrite is 5 (= 5 times heavier than water.) Fake or real??? Test... Review 1 What are the 7 tests? Color and appearance Hardness Luster Specific Gravity Streak Cleavage and Fracture Other Properties Review 2 Why do we sometimes need to do more than one test? It may be difficult to identify a mineral based on only one characteristic It may share common features with other minerals Review 3 Which test uses the Mohs scale? Hardness Review 4 What type of luster do each of... thin, flat sheets Halite cleaves at 90 degree angles Test 6 • Fracture: the physical property of some minerals that causes them to break with uneven, rough, or jagged surfaces Test 7 Test 7 • Other properties: some minerals have unique properties that allow them to be easily identified Magnetite will pick up iron like a magnet Test 7 Calcite can cause double images Test 7 These minerals “glow” in the... test uses the Mohs scale? Hardness Review 4 What type of luster do each of the following minerals have? (Metallic or Non-metallic) Metallic, non-metallic, non-metallic, metallic Review 5 What type of breakage do these minerals show? Cleavage, fracture, fracture Review 6 Which test is being performed here? Streak Test