Zircons are a fairly recent addition to the American National Jewellers Association’s list of monthly birthstones, having been added in 1952, replacing lapis lazuli. They are beautiful gemstones, with a high refraction, which means that they reflect a lot of light and so show intense sparkle and fire.
Zircons have been used in jewellery for thousands of years, known under various names, such as jargoon, and hyacinth or jacinth. The name ‘zircon’ was derived from either Arabic or Persian words around 1783.
They range in colour from shades of brown, yellow, blue, green and colourless (white). The colourless version was used often as a diamond substitute because it was so refractive and bright. The most common colour seen today is an intense blue. To achieve this depth of colour, the gems are heat treated.
Zircons have been confused with one of the more modern diamond substitutes, the synthetic cubic zirconia. Despite the similarity of name, the gems have different crystal structures and chemistry, and you can’t buy a natural cubic zirconia.