Exam 2: Minerals: Building Blocks of the Planet

You are a geologist hiking along a trail collecting rock samples. You come across a group of loose crystals which have broken away from the rocks, so you bring them back to the lab to figure out which minerals they could be. What tests can you put them through to figure out what they are? (2.1)

Why does lead have so many industrial uses?

Comparing the characteristics of two minerals, a student stated, "These two minerals are identical because they are both transparent and are six sided." Critique this statement.

From quartz's hard physical property, what can be inferred of its bonding structure?

One mineral is held together by van der Waal's forces and the other is held together by metallic bonds. Which is stronger?

Why does iron, when added to quartz, cause the purple color of amethyst?

Identify the physical mineral property described. "The fine-grained nature of the powdery residue results in a more reliable observed color."

Which mineral property depends on bond type and the spacing of atoms within the crystal?

Why does manganese, when added to calcite, cause the mineral to turn a deep red?

What do the minerals gold, sulfur, and talc have in common?

Under what conditions does a mineral most easily dissolve in water? (2.3)

Which minerals are most important? (2.7)

Which of the following is not a way that atoms achieve a full outer layer of electrons?

Briefly describe the concept behind a TEM detector. (2.4)

Ionic bonds are stronger than covalent bonds.

What is corundum? If it is not in the rare form described here, do we use it for anything?

Critique the following statement made by a student looking at a TEM image of dolomite. "The TEM image shows regular patterns of small dots, large dots, and tiny dots. The formula for dolomite is CaMg[CO3]2. I think the large dots must be the carbonate groups."

What variable will determine if light passes through diamond, but not through graphite?

In order for an atom to substitute for dominant atoms in a crystal structure, and therefore alter its color, what must occur?

Identify the physical mineral property described. "This property depends on the smoothness of the mineral surface at the atomic scale, or how mobile electrons are within the crystal."