GEOL 1403Lab Exercise: Minerals: GEOL-1403.295: Lab: Physical Geology.

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Question 1 1 / 1 pts Definition of a mineral. Geologists define a mineral as any naturally occurring, inorganic solid, with an orderly crystalline structure and a definite chemical composition. 1.... Naturally occurring. Minerals form through natural geologic processes. A mineral cannot be a manmade substance. A synthetic diamond or emerald is not considered a true mineral because it is not naturally occurring. 2. Inorganic. An organic substance is a compound composed mostly of oxygen, carbon and hydrogen where carbon atoms bond directly with hydrogen atoms. Simple sugar, carbohydrate and fat (Figure 1) are examples of organic substances. To be classified as a mineral, a substance must be inorganic. 3. Solid. Minerals are solid substances, not liquid or gas. 4. Crystalline. The atoms that make up a mineral are arranged in an orderly, repetitive manner. This orderly structure of atoms is reflected in the regularly shaped objects called crystals. 5. Definite chemical composition. The composition of a mineral can be expressed as a chemical formula that allows for some variation. A chemical formula provides definite proportions of certain atoms. For example, The chemical formula of quartz is expresses as SiO2 which indicates that quartz consists of silicon (Si) and oxygen (O) atoms, in a proportion of one-to-two. Select all the characteristics below that make up the definition of a mineral. possess a definite crystalline form inorganic material possess a definite chemical composition must be natural (not created by humans) must be a solid material Question 2 1 / 1 pts ____________ may become trapped within the crystalline structure of a mineral, causing slight changes to mineral properties (such as color). Impurities Question 3 1 / 1 pts Is petroleum (pictured below) a mineral? Select the properties of petroleum that match the properties of minerals. A mineral must meet all the criteria. You may need to look up the material online if you are not familiar with its properties. Naturally occurring Partial Partial Question 4 0.5 / 1 pts Are glass bottles (pictured below) a mineral? Select the properties of glass bottles that match the properties of minerals. A mineral must meet all the criteria. You may need to look up the material online if you are not familiar with its properties. Solid Question 5 1 / 1 pts Is pyrite (pictured below) a mineral? Select the properties of pyrite that match the properties of minerals. A mineral must meet all the criteria. You may need to look up the material online if you are not familiar with its properties. Crystalline Naturally occurring Inorganic Solid Definite chemical composition Question 6 2 / 2 pts For the following, select the word or phrase that best fits the mineral property description. Crystal habit is the shape of a mineral or group of mineral crystals. powdered, usually done by scratching the mineral on a porcelain plate called a streak plate. does not occur along a plane of weakness, or the mineral has no planes of weakness due to its chemical composition. Specific gravity is the ratio of the weight of a material or object and the weight of an equal volume of water; this is similar to density.[ Select ] consist of how light interacts with a mineral, such as (but not limited to) colors, reflectivity, opacity, luster, etc. [ Select ] is the color of a mineral when [ Select ] is the mineral's resistance to mechanical abrasion (i.e. being scratched). [ Select ] is the ability of a mineral to break along planes of weakness resulting from its chemical structure; a mineral may have more than one plane of weakness. [ Select ] is how minerals break when the break Answer 1: Answer 2: Answer 3: Answer 4: Answer 5: Answer 6: Answer 7: Crystal habit Optical properties Streak Hardness Cleavage Fracture Specific gravity Partial Partial Question 7 1.6 / 2 pts When testing the hardness of a mineral, we generally use items including the following: Fingernail (hardness of 2.5) Copper plate (hardness of 3.5) Glass (hardness of 5.5) Streak plate (hardness of 6.5) To find hardness, we try to scratch these objects with the mineral sample (or try to scratch the mineral with these objects). Answer 1: determine which objects will or will not be scratched by the mineral, we assign the mineral to a hardness range: Less than or equal to 2.5 (fingernail harness) Between 3 to 5 (can’t be scratched by fingernail but won’t scratch glass) Between 5.5 to 6.5 (can scratch glass and it leaves a streak) Greater than 6.5 (does not leave a streak as it is harder than streak plate) For example, if we find that a fingernail cannot scratch a mineral but the copper plate can scratch the mineral, the mineral's hardness would be between the fingernail (2.5) and copper plate (3.5). Thus the mineral hardness is likely about 3, putting it in the 3-5 hardness range. For the following, state the hardness range for each mineral based on each of the descriptions. Gypsum is easily scratched by your fingernail, it's hardness is [ Select ] . Feldspars (potassium feldspar, sodium plagioclase feldspar, and calcium plagioclase feldspar) can scratch glass, but leave a streak so they have a hardness of [ Select ] . Hornblende can scartch glass, and leaves a streak so it's hardness is greater than 6.5 . Quartz can scratch glass and does not leave a streak, so it's hardness is [ Select ] . Halite can scratch your fingernail but you cannot scratch halite with your fingernail. Halite cannot scratch copper, so it's hardness is [ Select ] .less than or equal to 2.5 Answer 2: Answer 3: Answer 4: Answer 5: between 5.5 and 6.5 greater than 6.5 greater than 6.5 between 3 to 5 Partial Partial Question 8 1.6 / 2 pts For the image below, select whether each mineral has a metallic or non-metallic luster. Hint - a metallic luster looks like metal - think stainless steel, silver, and gold. Sometimes metallic minerals may oxidize, leaving a dull metallic luster that's not very shiny. Answer 1: Answer 2: Answer 3: Answer 4: Answer 5: Mineral 16 is [ Select ] . Mineral 11 is [ Select ] . Mineral 15 is metallic . Mineral 7 is [ Select ] . Mineral 9 is [ Select ] [Show More]

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