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Roger Weller, geology instructor

cubic zirconia
by Melissa Richards
Physical Geology
Spring 2011


Cubic Zirconia

            Cubic Zirconia is known as a substitute for a diamond, this is because of its hardness and great fire. In recent years cubic zirconia has been recognized as a gorgeous gem in its own right. This gemstone is a beautiful and synthetic that is durable and inexpensive. Cubic zirconia comes in many colors.


        Cubic zirconia possesses a less sparkle but has more flashes of the rainbow. It is very hard but not quite hard as a diamond but can still scratch glass. Cubic zirconia is measured in carats but a more accurate measurement would be in millimeters. Cubic zirconia is heavier, weighing seventy-five percent more than diamonds. Another great difference between cubic zirconia and diamonds is that diamonds are thermal conductors while cubic zirconia is a thermal insulator.


            So what made it possible in the 1970s to produce cubic zirconia? That would be the invention of the microwave. The process to make cubic zirconia starts with the chemicals. Chemical reactions involved in making these gemstones forces the raw zirconium metal to be combined with oxygen. Two other components involved are calcium and yttrium, they act as stabilizers. This is to ensure that the metal and oxygen react and create the required crystalline structures.


        Then we have the heating process. The required temperature to affect the reaction is more than 4892 degrees Fahrenheit. The combined chemicals are placed into an industrial microwave. Once the microwave starts, the mass of chemicals will then heat up from inside out. The outer layer hardens and remains cool while the inside turns into a molten mass.


Next we need to harvest the gems. After the heating stage in complete, the “melt” as it is known, is left to cool gradually under controlled conditions. As they cool, the crystals of cubic zirconia form from molten core of the melt. Once they are fully cooled they can be cut into the required shapes and sizes.


       So what is cubic zirconia used for? Cubic zirconia is used to substitute diamonds. They are less expensive and almost look like real diamonds. They are used to make jewelry. For example, many engagement rings are cubic zirconia.



Works Cited

Roger Weller’s Website