Zircon is a semiprecious brittle stone found around the world that is located in metamorphic, sedimentary and igneous rocks. As the oldest stone on earth, it was once considered an alternative for the diamond. Ground into fine sands, it also has industrial uses in the manufacture of ceramics, glass, metals and chemicals.
As the ICA states, “Hindu poets tell of the Kalpa Tree, the ultimate gift to the gods, a glowing tree covered in gemstone fruit with leaves of zircon.” The oldest known object on earth is a tiny zircon that was located in Western Australia and is 4.404 billion years old, claims the American Gem Trade Association (AGTA). The name is believed to have come from the Persian word zargun, which means “gold-colored” or jargoon, which is the name given to certain varieties of the substance.
Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. It is a neosilicate, meaning that it is a silicate mineral that has isolated SiO4 tetrahedra, which are only connected through ionic bonds. When pure, zircon is colorless, but when other chemicals are introduced to it during its formation, zirconium silicate can become colored.
Exposure to sunlight may also even cause this change in color. It commonly is found with other stones, such as granite, sapphire and limestone. Its hardness on the Mohs scale is about 7.5. Some colors are black, yellow, brown, red and pink. Certain colors of this product may have different names.
Zircon can often be found with sapphires in Western Australia. It can also be found in Norway, the Rhine area, Central France, Russia, Canada and Tasmania. The substance is frequently mined in Cambodia, Sri Lanka, Vietnam and Thailand. In the United States, zirconium silicate can be located in New York and North Carolina.
Zircon ceramics often serve as protective coatings on metals. Most products get ground by processors into sands of varying grain size. Ceramics manufacturers make the most overall use of zirconium silicate, employing the finest sands to give their products high strength and high resistance to heat. Additionally, powdered zircon in ceramic glazes gives them an opaqueness that allows colors to stay fixed in varying light.
The famed cubic zirconium is a manufactured type of this compound. The natural mineral can also be cut, polished and set as a gemstone. According to the Zircon Minerals Council, roughly 12 percent of mined product becomes jewelry, although some of the crystals have to be heated to destroy the trace radioactive elements they contain.