What is Zircon? Zircon is the oldest known mineral crystal which belongs to the group of nesosilicates. They have been found in some igneous rocks which scientist believe date back 4.4 billion years ago. Its chemical name is zirconium silicate. Other interesting facts...Some Electrifying FactsWhat is a Lunar Eclipse?What are Deep Sky Objects?What is a light year?What the difference between a Meteor and a Meteorite?