Zircon is the oldest mineral on Earth, dating back more than 4.4 billion years. Found in the Earth’s crust, it’s common in most sand and sedimentary deposits, as well as metamorphic rocks and crystallized magma.
Due to its chemical makeup, zircon has survived ages of geologic events like erosion and pressure shifts—recording these changes like a time capsule. Zircon contains the radioactive element uranium, which changes the gemstone’s chemical structure and color over time, giving us important clues about the formation of our planet.
During the Middle Ages, people believed that zircon gemstones could induce sound sleep, ward off evil, and bring prosperity and wisdom.
Blue zircon, in particular, was popular during Victorian times, and frequently adorned English estate jewelry from the 1880s. Zircon with a cloudy or smoky appearance was also popular in mourning jewelry.
In the 1920s, heat treatment became customary practice to enhance the color of zircon gemstones for jewelry. Zircon has also been used in the decorative ceramics industry.
While zircon is a popular gemstone among collectors for its range of colors, consumers seem most enamored with the blue variety, and otherwise confused about the history and possibility of this expansive gemstone.
Zircon is often confused with cubic zirconia (CZ). CZ is one of the best-known, man-made diamond simulants and is the crystalline form of zirconium dioxide (ZrO2). Zircon is a naturally-occurring mineral, which is zirconium silicate (ZrSiO4).