The history of man made diamonds

Man made diamonds, also known as cubic zirconia, were first made in the 1930's when German scientists found that they could grow perfect crystals from zirconium oxide at very high temperatures. However they found it extremely difficult to manufacture because the man made crucibles holding the oxide couldn't really withstand the extremely high temperatures required.

The breakthrough came from the Soviet Union. In 1973, Soviet scientists at the Lebedev Physical Institute in Moscow, managed to create a crucible made of solid packed zirconia, to hold the zirconium oxide within it, while temperatures were increased to 2750 degrees centigrade to liquify the zirconium oxide to create the crystals.

The reason they were trying so hard to create cubic zirconia was because the Soviet space program needed optic lasers, which are usually made with diamonds. But the Russians couldn't really afford diamonds, and hence decided it was worth focusing their efforts on trying to make cubic zirconia, which they knew had similar properties to diamonds, being extremely hard and optically perfect. Indeed the crystal structure of cubic zirconia is more perfect than that of a diamond (and this is the main way to tell them apart from diamonds - cubic zirconia is flawless, whereas all real diamonds have minor flaws) and thus it makes cubic zirconia excellent for use in the manufacture of optical laser equipment and for other industrial use (eg cutting instruments)

Commercial production of cubic zirconia began in 1976. Because manufacturing cubic zirconia is extremely cheap compared to mining natural diamonds, it started to become popular in the manufacture of jewelry in the 1980's. The crystal glass specialists Swarovski and Co starting manufacturing cubic zirconia for jewelry and as part of their optical instrument business. Cubic zirconia not only costs about a tenth of the price of a diamond, but they can also be manufactured in a variety of colours, which gives the jeweller a lot of scope to make interesting jewelry. However most of the cubic zirconia manufactured is colourless and is used to simulate diamonds. They are cared for and cleaned in the same way as diamonds, and it's hard to tell just by looking at a social occasion whether someone is wearing cubic zirconia or diamonds, which makes them ideal for those who want glamour at a low cost.

For those who have inherited jewelry and are unsure whether it is made from diamonds or cubic zirconia, take them to a jeweller to assess measuring the heat conductivity of the gem. In the spectrum, cubic zirconia measures red, while diamonds measure green.