Lab_3a - Mineral identification

.docx

School

Palm Beach State College *

*We aren’t endorsed by this school

Course

GYL1000

Subject

Geology

Date

Apr 3, 2024

Type

docx

Pages

Uploaded by BaronElement12992

Lab_03: Mineral Identification Student Name: Fisher Charles Date: 02/02/2024 Mineral Identification Lab Introduction: In this lab activity you will become familiar with minerals and identifying their different properties. This lab will also introduce you to the deductive process where you will utilize the results of each property test to identify the name of the mineral from an established key. Materials:  ___ unidentified Minerals  Streak plate  Nail  Magnet  Penny Procedure: 1. Place your name, and date top of this sheet. 2. Read through the Pre-lab worksheet and answer the questions (page 2 & 3). 3. Self-check your answers at one of the stations set up around the room. 4. Get a mineral kit. Go through and test each mineral for:  Hardness  Color  Streak  Cleavage/fracture  Heft  Luster 5. Be sure to record all information in the data table YOU WILL NOT KNOW THE MINERAL NAME TILL THE END OF THE LAB. 6. As you’re testing your minerals, be sure to record your findings on your record sheet 7. After you have tested all minerals for all 6 properties, compare your test results for each mineral to the established mineral chart in the back. Use this chart to identify the mineral name. What did you learn after completing this activity? Write a conclusion paragraph below: I found the information about minerals to be quite enlightening. Exploring their properties was particularly enjoyable. Previously, I assumed gold was magnetic, possibly

due to the sight of people with metal detectors searching for gold on beaches. However, I now understand that pure gold is not magnetic, yet when fashioned into a coin, it can exhibit magnetic properties. An intriguing revelation is that my favorite mineral, Pyrite, shares nearly all the qualities of gold, which precisely explains its nickname, "Fool's Gold." Mineral identification Lab: Pre-lab worksheet Property Descriptions and Testing Procedures: Color : This is probably the most easily observed property of minerals. However, color often varies widely and is the least reliable property for identification. Streak : The color of the mineral when powdered. To test for streak, draw the mineral against an unglazed porcelain tile (streak plate). Streak is more useful for identification than color is. Hardness : A mineral’s hardness is it’s resistance to scratching . Mohs Scale of Hardness, this scale uses common everyday objects to test hardness of each mineral sample. Below is the resulting table. Moh’s scale of Hardness Rating Object used to test Hardness 1 2 3 4 5 6 7 8-10 Fingernail-2.5 Penny-3.5 Nail-4.5 Glass-5.5 Steel file-6.5 Streak plate-7 Diamond -10 Cleavage or fracture : These two properties refer to the way in which a mineral breaks. Cleavage is an orderly breakage in well-defined planes, meaning the mineral has flat sides. Fracture is a random breakage. If a mineral breaks with rough, random surfaces, it is said to have fracture. Heft : Compare the relative “heft” of a mineral by holding it in your hand and comparing it to other minerals of about the same size. In general, metallic minerals are heavier than non-metallic minerals. For ease, minerals are classified as 1.) light, 2.) heavy, 3.) very heavy. Luster : Refers to the way that a mineral reflects light. The simplest distinction is between metallic luster (shiny and gold or silver color) and nonmetallic luster (does not look like a metal in color, although it may be shiny). Particular types of nonmetallic

luster include pearly, vitreous (glassy), resinous (has the appearance of resin), silky, and earthy (dull). Other Tests: MAGNET TEST: if one of your rocks is attracted to a magnet, it may be magnetite. But check all the other properties too because other iron ores are also easily magnetized. Mineral identification Lab: Pre-lab worksheet Read through the lab handed out to you. Answer the following questions before you begin your lab. 1. What are the 6 properties used to identify minerals a. Colors b. Streak c. Sturdiness/Hardness d. Cleavage or Fracture e. Heft f. Luster 2. Briefly describe how you would test a mineral for each of these properties a. Color - Based on how the material looks and the quality it has externally. b. Streak - The color of the mineral when powdered when the mineral is drawn unglazed porcelain tile or a dedicated streak plate. Bonus if none of those things are available then a ceramic toilet lid can be used. c. Hardness - Using Mohs scale of hardness. Bonus Friedrich Mohs was a German mineralogist who introduced the Mohs scale of mineral hardness in 1812. d. Cleavage or Fracture - Cleavage is an orderly breakage in well-defined planes, meaning the mineral has flat sides. Fracture is a random breakage, if a mineral breaks with rough, random surfaces, it is said to have fracture. Bonus this phenomenon can sometimes be easily mistaken by students and is often the most difficult to master.

e. Heft – Hold it in your hand and compare it to other minerals around the same size check and determine whether the heaviness is on the Light/Medium/Heavy. Bonus metallic minerals are heavier than non- metallic minerals. f. Luster – (my Favorite) How it reflects light. Look at the sample to determine if the mineral is metallic in appearance or non-metallic. Bonus consider using a handheld magnifying lens or a microscope to closely inspect the mineral's surface. This can reveal finer details and subtle features that contribute to identifying its luster. 3. What tool is used to determine the streak of a mineral? _Streak Plate__________ 4. What is the name of the scale used to determine hardness? _Mohs Scale__________ 5. What is the difference between cleavage and fracture? Cleavage defines minerals breaking and creating a flat and smooth surface. While a fracture defines minerals breaking and resulting in jagged and rough surface. Cleavage mainly happens as a result of a minerals chemical structure, or you can say Internal Change. Where fracture mainly happens as a result of a minerals environment or External Change. 6. What are the two major categories of luster? Metallic and non-Metallic 7. List the various descriptions for Non-Metallic Luster  Pearly  Glassy  Resinous  Silky  Dull  Earthy

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help