Name the minerals below. Then, insert a percentage of how certain you are in your identification. Finally, explain your percentage of certainty: What was confusing about this mineral? What other minerals do you think it could be?
Remember, the minerals in the virtual lab include seven of the following: borax, calcite, corundum, graphite, gypsum, orthoclase feldspar, pyrite, quartz, talc, and topaz.
Identification of Mineral
Explanation of Certainty
I am almost certain this mineral is fluorite, but I am not completely sure. Fluorite and gypsum are both white, shiny, have white streaks, cleave, and show no reaction to acid. However, the specific gravity of this mineral is 3.18, which is higher than gypsum, so I am pretty sure it is fluorite. Mineral 1: Pyrite
I am almost sure that this mineral is pyrite because it is gold and has a black streak. The only thinks that do not match up is the specific gravity and the hardness. Mineral 2: Talc
I am certain that this mineral is talc because the hardness, specific gravity, color, streak and acid reaction are all the same. I am almost sure that this mineral is pyrite because it is gold and has a black streak. The only thinks that do not match up is the specific gravity and the hardness.. Mineral 3:Calcite
I am certain that this mineral is calcite because it is the only mineral on the list that is white and had an active bubbling acid affect. Mineral 4: Orthoclase Feldspar
I am almost certain that this mineral is orthoclase feldspar because everything matches but the hardness. The only other mineral it could be is corundum and the hardness is nine and I feel that that is way too high to be my mineral. My mineral matches best with orthoclase feldspar. Mineral 5:Quartz
I am almost certain that this mineral is quartz because it completely matches the description. Mineral 6: Gypsum
I am certain that this mineral is gypsum because the color, specific gravity, hardness, streak, luster and cleavage all match up to gypsum Mineral 7:Graphite
I am almost certain that this mineral is graphite. The only thing that does not match up is the acid reaction. When I ran the test I did not see any reaction with the acid but graphite does react to acid. I did not see any other options because the mineral is black and the streak is brown. So I am
almost positive that the mineral is graphite.
Part 3: Summary
Write a summary answering the following: What are the four requirements for a material to be classified as a mineral? How do you differentiate between minerals? Briefly summarize the six methods to tell minerals apart. Summarize the major differences between minerals and rocks.
For a solid to be classified as a mineral it must meet these four requirements: naturally solid, formed by inorganic processes, have characteristics of crystal structure, and a specific chemical composition. In order to tell minerals apart you can use these six methods: luster or color, streak, specific gravity, cleavage & fracture, hardness, and acidity. Luster is the intensity that light reflects off of a mineral. A mineral may be shiny, pearly, or even metallic. Some minerals may be distinguishable by their color. By dragging a mineral across a streak plate its mineral powder will leave a streak with a particular color, but this is not a very reliable way of identifying a mineral. By dividing the weight of a mineral in water by the weight of the water you can get the specific gravity of a mineral. Another method is by determining if the mineral has cleavage or fracture. When broken a rock will either be in rounded chunks, fractured, or it be flat with corners, cleavage. Using the Moh’s Hardness Scale you can determine minerals hardness. Hydrochloric acid placed on a mineral will determine whether a mineral contains calcium carbonate. The difference between minerals and rock is that rocks are aggregates. This means a collection of minerals that intergroup together; sometimes many kinds in one rock.