Unit 1 Assignment.docx

GEL111 - Earth Science 1 Rocks and Mineral Identification by Characteristics Steps GEL111 - Earth Science Unit 1 Assignment Professor Kinyo

GEL111 - Earth Science 2 Today, you and a friend will be hiking along the Merced River in the Sierra Nevada. As you walk, you will see sparkling golden stones at the water's edge. If you think back to your high school history class, you might remember that James Wilson Marshall discovered gold leaf here in 1848, leading to the California Gold Rush (History.com Editors, 2021). The question is, did you strike it rich? The following steps will help you decide if your minerals will make you laugh all the way to the bank, or if the bank will make you laugh "silly" with fake gold. Step 1 . Find and collect all the materials you need to perform tests that will help you identify each mineral. Materials needed for this activity:  Mineral and/or rock sample  Paper and pencil  Streak plate or unglazed tile  Scale (Digital or analog)  A penny  Steel blade (Metal knife)  Compass  Water  Soft bristle toothbrush  Bowl large enough for the mineral sample  String

GEL111 - Earth Science 3  Hammer Step 2 . Draw a table graph on a piece of paper for each sample you want to test. The table should consist of 11 rows and 2 columns. Each row in the first column names one of the 11 tests to be performed. Leave the second column blank so you can write down your test results. Leave space for notes that may be important to the identification process. Step 3 . Remove the rubber duck and add clean tap water. Specimens must have the correct shape, color and luster to be easily recognized. Using a toothbrush, gently brush the sample with water. Remove any dust or debris that may obscure the test results. Allow the specimen to dry before performing the test. Step 4 . First, the luster of the mineral sample should be checked. We chose this test to ensure that the surface of the mineral is not altered by other tests. This gives the best results when testing minerals. To measure luster, look at how light reflects off each mineral sample. Luster refers to the overall gloss of the mineral surface and has nothing to do with color (Key to Mineral Identification, 2003a). Record the level of gloss you observe in the appropriate row of the table. (eg matte, glass, metal, etc.) Step 5 . This is the life of a hard rocker. The hardness of a mineral sample should be determined using the Mohs hardness scale. The Mohs scale of hardness is known as relative hardness and is used to compare the hardness of a material with the previously known hardness of the material (Mineral Identification Key, 2003b). This is a scratch test. Use mineral samples to shave nails, coins and steel blades. If a mineral sample doesn't scratch your nail, you'll know its hardness is less than 2.5. This is because we know that nails are 2.5 on the Mohs hardness scale. When the mineral pattern scratches a steel blade, you can see that its hardness is greater than 5.5.

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GEL111 - Earth Science 4 Record the results for each mineral sample on the appropriate line in the table chart. For examples of hardness, see the hardness table. Figure 1: Image of Mohs Hardness Scale (Mohs Hardness Scale, 2018). Step 6 . Then we begin to determine the color of the mineral. Color is very important in identifying minerals. First, make sure the mineral sample is examined under bright light. This ensures an accurate representation of the color of the mineral sample. Samples can also be examined for fluorescence, iridescence, or color changes. Document the results in the appropriate rows of the table diagram. Step 7 . The color work is not finished yet. Now let's try some mineral style bars. The color of the band is the color of the mineral's powder form (Mineral Identification Key, 2003c). Sometimes this color may differ from the original color. Using a stripper or polishing pad, slowly drag the mineral sample across the surface, applying enough pressure to leave a band.

GEL111 - Earth Science 5 Check the deposited powder under bright light to determine the exact color of the powder. Record the results in the appropriate row of the table. Step 8 . Have you decided to make mineral detecting a habit? In any case, the habits of the mineral specimen must be determined. Common mineral shapes include thin, tubular, and odd shapes. (Keys to Mineral Identification, 2003d). Please refer to the attached custom definition table for reference. Document the results in the appropriate rows of the table diagram. Figure 2: Picture of Habits (Habits, 2012). Step 9 . The magnetism of mineral samples can be tested. However, this is not a key characteristic of many minerals. Use the compass to move the compass over the mineral sample. When a mineral becomes slightly magnetized, the compass needle moves north (Reading Area: Mineral Detectives, 2006). Record the results in the appropriate rows of the table diagram. Step 10 . Now it's time to measure the specific gravity of your mineral sample. This is the density of the mineral. This can be interpreted as the amount of mass per unit volume or the amount of space a mineral occupies relative to the amount of material that makes up the mineral (density, n.d.). Since different minerals have different gravitational forces, this helps to better

GEL111 - Earth Science 6 identify mineral samples. To perform this test, weigh a sample of the mineral and record its weight. Then fill the container with enough water to cover the minerals. Place the pan on the scale and set the scale to zero. Tie a string around the mineral sample, suspend it in water while the dish is on the scale, and record the weight. Divide the dry mineral weight by the wet mineral weight. Document the results in the appropriate rows of the table diagram. Step 11 . Another important property to evaluate is mineral separation. Cleavage is how minerals break apart along weak lines in their structure (Key to Mineral Identification, 2003e). Look at the mineral and see if it has a smooth, flat surface that reflects light. This shows the separation of mineral samples. Record the results in the appropriate rows of the table diagram. Step 12 . Nothing in life is always smooth sailing. Therefore, it is necessary to check whether the mineral sample is fractured. Cracking is the breaking of a mineral in a random pattern without a smooth surface (fracture | mineralogy, etc.). Similar to the split test, we look at the surface but find that there is no smooth surface. Record the results in the appropriate rows of the table diagram. Step 13 . Almost ready. Stay calm and don't give in to pressure. Speaking of cracking, the final test consists in determining the fracture resistance of the mineral sample. This is known as hardness and is a measure of the malleability or brittleness of a mineral (Key to Mineral Identification, 2003d). Performing this test will damage the mineral sample. You must proceed with caution. The mineral samples were hammered. When a mineral breaks down, it becomes brittle. If the sample changes shape easily without breaking, it is ductile or malleable. You can also test the mineral by splitting it with a knife. If this is possible, your mineral is sextile. If you are brave enough to destroy a mineral sample, record the information in the appropriate row of the table diagram.

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GEL111 - Earth Science 7 Congratulations. We have completed a series of tests to determine what the mineral samples are. Visit Minerals.net where you can use your registered information to apply filtered searches to the site and determine if your mineral is a match. Compare and Contrast of Four Mineral Samples Diamond Dolomite Gneiss Chalk Luster Adamantine Vitreous, pearly Dull Dull Hardness 10 3.5 – 4 5.26-6.47 1-2 Color Colorless, white, yellow, brown, gray, black, green, red, orange, pink, or purple. Colorless, white, gray, reddish- white, brownish- white, or pink. Black, brown, pink, red, and white. White, yellow, and grey. Streak White White White White Specific Gravity 3.1 - 3.53 2.8 - 3.0 2.5 - 2.7 2.3 - 2.4 Magnetism No No No No Cleavage Yes Yes No No Tenacity Brittle Brittle Brittle Brittle

GEL111 - Earth Science 8 References Density . (n.d.). Study.Com. Retrieved 2022, from https://study.com/academy/lesson/density- lesson-for-kids-definition-facts.html fracture | in mineralogy . (n.d.). Encyclopedia Britannica. Retrieved 2022, from https://www.britannica.com/science/fracture-in-mineralogy Habits . (2012). [Illustration]. Geology In. https://www.geologyin.com/2019/10/crystal-habits- and-forms.html History.com Editors. (2021, April 16). California Gold Rush . HISTORY. Retrieved 2022, from https://www.history.com/topics/westward-expansion/gold-rush-of-1849 The Learning Zone: Mineral Detectives . (2006). Oxford University Museum. Retrieved 2022, from http://www.oum.ox.ac.uk/thezone/minerals/detect/other.htm Mineral Identification Key . (2003). Minsocam.Org. Retrieved 2022, from http://www.minsocam.org/msa/collectors_corner/id/mineral_id_keyi1.htm Mohs Hardness Scale . (2018, February 6). [Illustration]. National Park Service. https://www.nps.gov/articles/images/Mohs_Scale2_1.jpg? maxwidth=1200&autorotate=false&quality=78&format=webp