Earth Science: Geology, the Environment, and the UniverseChapter 4: MineralsProblem of the WeekGem Sleuths Have you ever heard the saying "A diamond is a girl’s best friend?" What’s that about? Why are diamonds so valuable? What makes a gem, a gem? Gems have been sought after, and marveled at, for thousands of years and yet, they are just minerals. Gems or gemstones are valuable because they have several valuable characteristics: beauty, rarity, durability, demand, tradition, and portability. Because they are rare, they are expensive. People have been trying to synthetically duplicate gemstones for many years, sometimes with great success, sometimes not. A synthetic stone is defined as "a substance
which has been produced artificially, and which has the same chemical
composition, crystal structure and physical properties as its natural
counterpart." As synthetic gemstones become more common, it is important
for gemologists, jewelers, and consumers to be familiar with the properties
and characteristics of the real thing and the synthetic. How does one
tell a synthetic gem from the real thing? Since gems are minerals, characteristics
such as luster, hardness, streak color, density and specific gravity,
can be used to identify the gem. Another important characteristic, the
presence of inclusions, is also helpful in distinguishing a natural gem
from a synthetic gem. Many natural gems contain tiny inclusions of other
minerals. And many synthetic gems will contain small gas bubbles and faint
growth rings. In some cases it may be nearly impossible to tell a natural
gem from a synthetic gem. Situation: You are a gemologist. A customer comes to your
shop with two emeralds that they have inherited and they want to know
how much to insure them for. You know that emeralds are some of the most
successfully synthesized gems and because of this you know you must carefully
analyze the gems. Problem: You go to work and come up with the information in the table below. Use this information and the information from the web resource pages to determine whether these gems are real or synthetic.
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