14. Determine whether the following have cleavage or fracture. If cleavage is present, what is the shape and number of cleavage directions? a. Quartz None b. Galena fracture c. Muscovite mica one direction d. Feldspar Two directions of 90 degree angles. 15. Put a small drop of vinegar on the following samples (use the small bottle provided with the mineral testing kit). Describe what happens and why. Note: you may have to scratch the surface of the minerals or warm up the vinegar to get the necessary outcome! a. Quartz The vinegar sat on top of the rock, but slid into the scratched spot. b. Calcite Half the vinegar ran off. c. Graphite The vinegar ran off the rock. d. Talc The vinegar went through this soft rock. 16. Observe the minerals in Figure 1.3B of your lab book (p. 4). All four of the minerals shown are varieties of the same mineral, quartz. Also, examine the sample quartz in your ‘ Ward’s Economic Minerals and Rocks Set’. What is the reason for the variety of colors that quartz exhibits? Quarts are minerals and minerals are natural resources. Man has no control over the coloring of minerals.
MineralName | Color | Luster | Streak | Hardness | Cleavage | SpecialProperties | Vinegar Reaction | 1.Barite | Blue | Non Metallic | None | 3 | None | None | Nothing |