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Geosciences LibreTexts

7.11: Lab Exercise (Part C)

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    5587
  • Overview

    Take out Minerals Bag 3 and lay the six mineral samples out on a white sheet of paper. It should appear like Figure 7.21. We will first examine several properties, including streak, from these six samples, and will answer more questions about them later in the lab. Look closely at each of the minerals, using the hand lens to observe them. In this bag, you have the following minerals (not listed in order): Magnetite, Graphite, Copper, Sulfur, Hematite, and Pyrite. They are numbered 13-18.

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    15. Sample 13: What is the streak of this sample?

    a. dark gray streak

    b. white streak

    c. reddish brown streak

    d. pale yellow streak

     

    16. Sample 13: What is the luster of this sample?

    a. non-metallic, vitreous

    b. non-metallic, earthy

    c. non-metallic, greasy

    d. non-metallic, waxy e. metallic

     

    17. Sample 14: What is the streak of this sample?

    a. dark gray to black streak

    b. white streak

    c. reddish-brown streak

    d. pale yellow streak

     

    18. Sample 14: Which other item(s) is/are characteristic(s) of this sample?

    a. stains the fingers

    b. harder than glass

    c. greasy feel

    d. both a and b

    e. both a and c

     

    19. Sample 15: What is the streak of this sample?

    a. dark gray to black streak

    b. white streak

    c. reddish-brown streak

    d. pale yellow streak

     

    20. Sample 16: What is the luster of this sample?

    a. non-metallic, vitreous

    b. non-metallic, earthy

    c. non-metallic, greasy

    d. non-metallic, waxy

    e. metallic

     

    21. Sample 16: Due to its appearance, this sample has often been confused with native gold, a mineral with a hardness of 2.5-3. How does its hardness compare with that of gold?

    a. Sample 16 is harder than gold.

    b. Sample 16 is softer than gold.

     

    22. Sample 17: What is the streak of this sample?

    a. dark gray to black streak

    b. white streak

    c. reddish-brown streak

    d. pale yellow streak

     

    23. Sample 17: What another unique property does this sample have?

    a. effervescence in acid

    b. it is magnetic

    c. it tastes salty

    d. it feels soapy

    e. it writes on paper

     

    24. Sample 18. Examine this entire sample closely with a hand lens. What is the luster of this sample?

    a. non-metallic, vitreous

    b. non-metallic, earthy

    c. non-metallic, greasy

    d. non-metallic, waxy

    e. metallic

     

    Now that you have had practice at detecting the properties of your 18 mineral samples, take the next step of identifying each sample and answering the questions below. Use the Mineral Identification Chart (Figure 7.22) to help you.

     

    25. Sample 1: What is this sample?

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    26. Sample 2: What is this sample? 

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    Mineral Identification Chart

    Luster Hardness Cleavage Other Properties Mineral Name
    Non-Metallic > Glass Poor Cleavage Red-brown, black, silver in color. H=6. St=red-brown Hematite
    Olive-green in color. H=6. St=white. Commonly granular Olivine
    Variety of colors. H=7. Conchoidal fracture. Vitreous luster. Quartz
    Clearly Shows Cleavage Black to greenish-black in color. H=6. C=2 planes at ~60° and 120°. Elongated crystals. Amphibole
    Tan-pink, white, green in color. H=6. C=2 planes at 90°. Microcline
    Black to greenish-black in color. H=6. C=2 planes at ~90°. Short stubby crystals. Pyroxene
    < Glass Poor Cleavage Dark gray to black in color. H=1. Greasy feel - will smudge fingers. Graphite
    Yellow in color. H=1.5-2.5. St=white to yellow. Sulfur
    White to green in color. H=1. Soapy feel. Talc
    Clearly Shows Cleavage Brown to black in color. H=2.5. C=1 perfect. Breaks into thin sheets that are elastic. Biotite Mica
    White to transparent in color. H=3. C=3 rhombohedral. Strong effervescence in acid. Calcite
    Transparent, yellow, purple, green in color. H=4. C=4 - octahedral. Fluorite
    Transparent to white in color. H=2. C=3, though 2 directions may be difficult to see. Gypsum
    White to transparent in color. H=2.5. C=3, cubic. Tastes salty. Halite
    Transparent, light brown, to yellow in color. H=2.5. C=1 perfect. Breaks into thin sheets that are elastic. Muscovite Mica
    Metallic > Glass Poor Cleavage Black in color. H=6. St=black. Strongly magnetic. Magnetite
    Brass-yellow in color. H=6.5. St=dark gray. Pyrite
    < Glass Poor Cleavage Copper-red in color. Tarnishes to green or black in air. H=2.5-3. St=copper-red. Copper

     

    27. Sample 3: What is this sample?

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    28. Sample 4: What is this sample?

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    29. Sample 4: What other unique property does this sample have?

    a. effervescence in acid

    b. it is magnetic. 

    c. it tastes salty. 

    d. it feels soapy. 

    e. it writes on paper. 

     

    30. Sample 5: What is this sample?

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    31. Sample 6: What is this sample?

    a. Microcline

    b. Fluorite

    c. Quartz

    d. Olivine

    e. Talc

    f. Selenite (Gypsum)

     

    32. Sample 7: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    33. Sample 7: What other unique property does this sample have?

    a. effervescence in acid

    b. it is magnetic. 

    c. it tastes salty. 

    d. it feels soapy. 

    e. it writes on paper. 

     

    34. Sample 8: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    35. Sample 8: What other unique property does this sample have?

    a. effervescence in acid

    b. it is magnetic. 

    c. it tastes salty. 

    d. it feels soapy. 

    e. it writes on paper. 

     

    36. Sample 9: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    37. Sample 10: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    38. Sample 10: Test this tenacity of this mineral by trying to bend it. Which way does it behave?

    a. sectile

    b. malleable

    c. elastic

    d. brittle

     

    39. Sample 11: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    40. Sample 12: What is this sample?

    a. Pyroxene

    b. Muscovite Mica

    c. Halite

    d. Amphibole

    e. Calcite

    f. Biotite Mica

     

    41. Sample 13: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    42. Sample 14: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    43. Sample 15: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    44. Sample 16: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    45. Sample 17: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    46. Sample 18: What is this sample?

    a. Magnetite

    b. Graphite

    c. Copper

    d. Sulfur

    e. Hematite

    f. Pyrite

     

    Mineral Notation Chart

    Fill in this chart as you work through the lab. An example of a mineral you do not have in your kit (#0) is included. You do not have to fill out every column for every mineral – just follow along in the lab and determine the properties you are asked about.

    Mineral # Luster Hardness Cleavage/Fracture Streak Other Notable Properties (include color when diagnostic) Name
    0 Metallic ~2.5 – May scratch fingernail 3 - cubic Gray High specific gravity because it is heavy Galena