The metallic element Zirconium is twice as abundant in the earth’s crust as either copper or zinc. It it ten times more abundant than lead. Zirconium is not found in nature in its native state. It is always bound up in compounds, the most common of which is zircon, a neo-silicate, ZrSiO4.
Zircon is hard and dense and can be cut and polished as a semi-precious gemstone. It is also used directly in many commercial applications such as refractories, metal molds, and laboratory crucibles. About 60 million tonnes are mined annually. Of that quantity about one million tonnes of pure zirconium metal is extracted.
Zirconium metal is resistant to corrosion and thus used as an alloying agent. Pure zirconium is used as cladding for nuclear reactor fuels.
Cubic zirconia is the synthetic oxide form (ZrO2) of zirconium. It is used as a substitute for diamonds. The natural form of zirconia is too rare and thus it has to be made in the lab.
Zirconium is not a biologically active metal and humans consume a few milligrams of it every day in their food and water.
Here’s a zircon specimen from Crystal Classics Fine Minerals: