Zircon occurs in a wide spectrum of colours including yellow-golden, red, brown, blue and green. For many years, the most popular was the colourless variety which looks more like a Diamond than any other natural stone due to its luminosity and dispersion. Some gem collectors believe that Zircon is the most brilliant natural gem that exists and it has been set into jewellery since antiquity. Historically the gem was known as Hyacinth, after Pliny the Elder described the gem’s colour as similar to that of the flower. Its modern name Zircon is said to have been derived from either the Persian language, simply meaning “golden coloured” or from the Arabic word for red, “zarkun”. As one of the oldest gems to be set into jewellery, it may not be surprising that it has been known by many different names in the past. With its Diamond- like appearance, for a period it was known by many in the trade as the Matara Diamond. This name was soon abandoned, however, as it was often fraudulently sold as a real Diamond. Blue Zircons have previously been referred to as Starlight and many on the market achieve their colour through heat treatment. Yellow Zircon, straw-like in colour, was known as Jargon, and Red Zircon was known as Jacinth (this is how it is recorded in the Bible). Today, life is a little simpler and we tend to describe different coloured Zircons by simply prefixing them with their hue (e.g. Blue Zircon, Yellow Zircon etc).
One of the reasons the gem has such amazing brilliance is that it is doubly refractive (also known as birefringence). As light enters the gem, it splits in two and effectively the facets on the pavilion act like a wall of mirrors, sending its double rays in different directions. When you combine this with the fact that it has an adamantine lustre, you begin to realise why it is often confused with Diamonds.
Zircon is said to be the oldest gem on earth and is far older than even the most ancient Diamond! In 1984, Dr Simon Wilde (a university professor) discovered a sparkling Zircon while searching for gold in the Jack Hills of Western Australia. Four years later Wilde met up with another professor, John Valley, and together they performed a series of scientific tests on the Zircon and were able to ascertain that it was an incredible 4.27 billion years old! Later they tested other Zircons from Wilde’s collection; using a £1.5 million spectrometer, they were amazed to find one specimen that was formed 4.4 billion years ago. This result contradicted other scientists’ research, who previously did not believe that Earth was first formed from a dense body of gas and dust 4.4 billion years ago. Thus, after Valley and Wilde’s Zircon discovery, scientists now believe the earth was formed around 4.5 billion years ago, making Zircon the oldest gemstone on the planet.
By studying the construction of the gem, scientists have been able to gain a far better understanding of how the Earth was actually created. It indicates that in its early stages, Earth was far cooler than it was initially believed to be, lacking the meteorite onslaught geologists had previously imagined (how clever to be able to tell all that from a gemstone).
In the Middle Ages, Zircon was believed to induce sleep, and encourage honour and wisdom. It was said to bring prosperity to its owner and thought to drive away plagues and evil spirits. It was also believed to increase ingenuity, glory and wealth and would prevent travel-sickness. During the Black Death it was also worn as a protective talisman.
Purely because of its similarity in name to Cubic Zirconia, today this most glorious and ancient, genuine gemstone often wrongly gets confused with the man-made Diamond look-a- like. With a hardness of 7.5 on the Mohs Scale, Zircon perfectly fits the description of a top quality gem: it is rare, extremely beautiful and very durable. The gem is often rich in the metal “zirconium”, which is a metal now famous for its use in nuclear reactors and its name suggests it is derived from the gemstone. Zircon is currently mined in such countries as Cambodia, Australia, India and Brazil.
One last thought on Zircon; next time you are wearing a piece of Zircon and its stunning sparkle or dispersion catches someone’s eye, be sure to pass on the news that you are in possession of a piece of history. Right there on your finger is a crystal that possibly started its journey at the same time as Earth first started to spin.