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The Gemstone Marketplace

Carl Wozniak, G.G.,

Purpose:

Gemstones are handy materials that can be easily used to integrate science and other fields of study in the classroom. In this exercise, your group (country) is provided with a number of different gemstones. These represent the raw resources of your country.

As in the real world, different countries have different types and quantities of resources. Your task is to maximize the value of your mineral resources, both for your country and yourself, through trading. You will be working as part of a group, but you will be able to permanently keep any resources in your personal possession at the end of the exercise.

Gemstones have both intrinsic and extrinsic value. Intrinsic value stems from factors such as rarity, durability, processing costs, and usefulness. Extrinsic values result from things like beauty, demand, and personal desire or appreciation.

Task:

Maximize your countries wealth (along with your personal wealth) by trading resources with other countries.

Procedure:

  1. Use the supplied key to identify your resources and their relative value.
  2. Determine the overall value of your country’s entire resource supply (count the number of $ signs).
  3. Determine (as a group) what resources you would like to acquire through trading. A successful country likely needs a variety of resources. As a group or individually, trade with other countries. (Note: you do not have to share your strategies for gaining personal wealth with the rest of the group.)
  4. Trade with other countries. This may be done as a whole country, as subsets of the entire group, or individually.
  5. Return to your own country and determine the value of your resources (count $ signs).
  6. You may redistribute your resources among the country’s partners through trade or some other mechanism, or elect to keep what you have earned.
  7. Pocket your goodies.

Analysis:

  1. Did your country profit from its trading? Note that “profit” is not just a function of maximizing monetary value. What other factors might be considered “valuable” with regard to your resources?
  2. What effect did new information have on the trading process?
  3. Do you believe that some members of your country ended up in a better financial position than others? Is this fair?

Stone / Description / Value
Diamond / Diamond is composed of carbon and is extremely hard, beautiful, and valuable gemstone. When cut, it is noted for its brilliance, play of colors, scintillation, and durability. Unfortunately, a number of simulants, namely cubic zirconium (CZ, value $$) and moissonite (value $$$), are occasionally sold as diamonds by unscrupulous dealers. CZ is softer, heavier, and has greater dispersion than diamond. / $$$$$$
Corundum / Corundum is an aluminum oxide mineral. Red corundum (caused by a chromium impurity) is known as ruby. All other colors are known as sapphire (mostly iron or titanium impurities). At a Mohs scale of 9, corundum is hard and durable. The deepest red (“pigeon blood”) and deepest blues (“Ceylon”). Synthetics are common (value $) Stones may be faceted or cabochons. / $$$$
Beryl / The most well known beryl gem (beryllium aluminum cyclosilicate) is emerald (trace of chromium), which is also the most valuable. Aquamarine (blue-green) and morganite (pink) are slightly less valuable. / $$$$-$$$
Peridot / Peridot is the gem version of olivine and is easily distinguished by its yellow green color. It is a magnesium iron silicate, and is usually found in the trade as faceted stones. / $$$-$$
Opal / A hydrated silicon dioxide, precious opal demonstrates opalescence, a play of colors. Opals can have a background color of white, gray, blue, or black. The highest value opals have extreme play of color, with red and green being the most valuable. / $$$$-$
Quartz / Quartz is a silicon dioxide and comes in many forms. Clear quartz is known as rock crystal.
Smoky quartz is caused by irradiation. Amethyst (purple) is caused by an iron and aluminum impurities. Citrine (yellow) is caused by iron impurities. Most market citrine is actually heat-treated amethyst. Rose quartz is rarely transparent. The pink color is due to titanium, iron, or manganese. / $$$-$
Opal / A hydrated silicon dioxide, precious opal demonstrates opalescence, a play of colors. Opals can have a background color of white, gray, blue, or black. The highest value opals have extreme play of color, with red and green being the most valuable. / $$$$-$
Pearl / Pearls are organic gems (as are amber, fossils, jet, coral, and ivory). Pearls naturally may be shades of white, pink, gray, or black, but many market pearls are artificially dyed. The shimmering of pearls is called orient or pearlescence. / $$$$-$
Garnet / Garnets are iron, magnesium, or calcium silicates. They come in many colors, with almandine (deep red) and pyrope (purple red) being the most common. Most garnets are some variety of red, but green (tsavorite), and orange (spessartite) are also found. / $$$-$
Cryptocrystalline quartz / Some gem materials are made of very small quartz crystals. These materials are known as chalcedony (white or lightly colored), agate (translucent multi-colored and banded), jasper (opaque red to brown), aventurine (usually green, with mica inclusions that shimmer), tiger eye (gold to red-brown with chatoyancy), and onyx (usually black agate with straight bands) / $$-$
Labradorite / Labradorite is a feldspar mineral. Gemstone varieties exhibit a high degree of iridescence (called labradorescence) that is observed as dark, metallic shimmers in blue and green. / $$-$
Petoskey Stone / Petoskey stone is the polished Middle Devonian coral fossil Hexagonaria. The stones have been naturally eroded by glaciation. When polished, the coral cells are clearly visible. / $$-$
Celestite / Celestite is a strontium sulfate and is characterized by soft, pale blue-gray (“celestial”) crystals that come to collectors mostly from Madagascar. While not a gem material, it is a frequent inhabitant of mineral collectors’ display cases due to its beauty. / $
Pyrite / Pyrite is a shiny, brassy, metallic iron sulfide mineral. Pyrite is sometimes used as a low-grade gem material, but many people collect the crystals for their own beauty. Called “fools gold” for its color and luster, be careful not to be deceived by unscrupulous dealers. / $

Addressed Benchmarks for Scientific Literacy, Project 2061, AAAS

  • Grades 3-5
  • A lot of different materials can be made from a small number of basic kinds of materials (p. 77)
  • Grades 6-8
  • Some minerals are very rare. As minerals are depleted obtaining them becomes more difficult (p. 69)
  • Different arrangements of atoms into groups compose all substances (p. 78)
  • Grades 9-12
  • Atoms often join with one another in various combinations in distinct molecules or in a repeating three-dimensional crystal patterns (p. 80)
  • The configuration of atoms in a molecule determines the molecule’s properties (p. 80).

Carl Wozniak,