ESSE1012_lab2_2024

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LE/ESSE 1012 3.0 The Earth Environment Winter 2024 Lab. Section: M Name: Sadaf Bayat Student Number: 219267475 LAB 2: MINERALS Due February 2, 2024, 10PM ET IMPORTANT: This is a hands-on lab. You must attend the lab session in person in order to receive credit for this lab. Unless otherwise indicated, show your work for all problems. You can either enter your answers into this document electronically using a computer or tablet, or you can print this document, handwrite your answers in the spaces provided, and scan the pages. If you need additional space, you can insert additional pages or you can add additional space within the Word document. For all numerical answers, the units should be indicated. Students can discuss this lab with each other, but copying from each other or copying from other sources is cheating and is not permitted. You should not share your answer sheets with other students or look at the answer sheets of other students. You should understand the concepts well enough to explain your answers in your own words. Your answers for hands-on portions of the lab should be based on work that you yourself performed in the lab location. If the lab procedure indicates that you can form groups to complete particular tasks, then you should still be physically present in the lab location contributing to the completion of those tasks, and you should write the names of other group members on your answer sheets. If your work relies on information that is obtained from a legitimate source other than ESSE 1012 course materials, please indicate the source of that information with enough detail so that someone else can locate the source. Please see the course outline for detailed policies. Although there are thousands of known minerals, over 99% of the rocks on Earth are made up of fewer than 20 minerals. In this laboratory exercise, you will examine the properties of these 'rock forming' minerals. The goal of this lab is to have you use the physical properties of crystalline solids to identify common rock forming minerals. In the process, you will use Tables A.1 and Table A.2 from the Jarvis text (available on eClass), along with the concepts covered in the lecture and Chapter 7 of the McConnell text . LE/ESSE 1012 Lab 2 - Winter 2024 ©NTandon Page 1 of 7

1. COLOUR, STREAK AND LUSTRE You are provided with the following samples: Mineral Name Lustre Pyrite Metallic Quartz Vitreous (glassy) Kaolinite Dull Earthy Talc Pearly Examine each sample and be sure that you can recognize each type of lustre before moving on. Use the streak plates (made of unglazed porcelain) along with your recently acquired knowledge of lustre to determine the colour, streak and lustre of the given minerals below. Non-Silicates: magnetite oolitic hematite limonite sphalerite galena pyrite Silicates: kaolinite amphibole garnet a) Complete the following table from your results (3 marks for each mineral) Mineral Colour Streak Lustre Magnetite (#71) Dark gray Black metalic Oolitic hematite (#75) Brown red brown dull earthy Limonite (#73) ton brown yellow brown dull earthy Sphalerite (#66) silver dark gray metalic Galena (#77) dark gray dark gray metalic Pyrite (#78) greenish gold greenish gold metalic Kaolinite (#82) white white dull earthy Amphibole (#62) gray nothing vitreous LE/ESSE 1012 Lab 2 - Winter 2024 ©NTandon Page 2 of 7

Garnet (#67) brown nothing vitreous b) Was streak colour useful for all of the minerals? Why or why not? If not, indicate the lustre(s) of the mineral(s) for which streak was not useful. Was there a particular group that streak was useful for? (4 marks) No it was not useful for all of the minerals. For vitreous lustre was not helpful because we could not see any thing at all. And the minerals are amphibole and garnet. Yes for dull earthy and and metallic it was helpful. c) Suppose that you encounter a rock sample with earthy lustre, and you wish to determine its mineral composition. One portion of the rock sample produces a reddish brown streak and another portion of the rock sample produces a yellowish brown streak. How would you interpret these results? (4 Marks) When one comes across a piece of earthy-colored rock, one can deduce the mineral composition based on the different hues of the streaks. Oolitic hematite (#75), a brown- colored mineral with a reddish-brown streak and a dull, earthy luster, is most likely the section of the sample that produced this pattern. Similar to limonite (#73), which likewise has a dull earthy luster and a ton brown tint, the yellowish-brown streak seen in another area of the rock sample matches its characteristics. According to the interpretation, the rock sample may contain minerals like limonite and oolitic hematite, which both have an earthy luster with matching streak hues. It is recommended that additional analysis be carried out, including mineral assays for a more accurate determination of the rock sample's mineral makeup. d) Pyrite is commonly known as “fool’s gold” because it has some physical properties similar to gold. Give two different physical properties that you would use to identify pyrite as distinct from gold? (4 Marks) Because pyrite, also referred to as "fool's gold," resembles gold in some visual aspects, it is important to distinguish it by its unique physical characteristics. Their different colors are one of the main things that set them apart. Whereas pyrite usually has a lighter, brassier yellow color, gold has a rich, deep yellow hue. Even though it is slight, this variation in pigment is an important feature to consider when evaluating the minerals visually. Another useful technique for distinction is to take the minerals' hardness into account. Pyrite is noticeably tougher than gold, which is rather delicate and easily scraped with a fingernail or knife. A basic hardness test can be used to determine this difference, since pyrite is harder and gold is more prone to scratches. One can confidently distinguish pyrite from gold by closely scrutinizing both color and hardness, and so avoid the misunderstanding that pyrite is "fool's gold." LE/ESSE 1012 Lab 2 - Winter 2024 ©NTandon Page 3 of 7

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