A created gemstone is one that is made in a laboratory, but which shares virtually all chemical, visual, and physical characteristics of its natural mined counterpart. In some cases, namely synthetic turquoise and synthetic opal, additional compounds can be present. Created gemstones are known in a variety of names, such as synthetic, man-made, lab-grown, and lab-created.
Due to their creation within a controlled environment, synthetic gemstones often have fewer inclusions and more intense colors than natural gemstones. However, depending on the growing process, lab-grown stones can have the same amount of inclusions and flaws found in natural stones - making them difficult to distinguish from their natural counterparts.
There are various methods of creating synthetic gemstones; some are relatively inexpensive, while others are more expensive. Because synthetic gems for jewelry use can often be made-to-order with consistent color and shape if given the right ingredients, time, and the facilities to grow them, they are likely to be much less rare than natural gems of equal size, clarity, and color saturation.
Synthetic gems have been manufactured since the late 1800s, and their production is often marked by demand in industrial applications outside of the jewelry industry, such as for use in laser technology, microelectronics, and abrasives. The first success in creating a synthetic gemstone was in producing synthetic ruby.
The rise of synthetic gemstones began in the 1920s, with an emphasis on delicate, gemstone-set jewelry designs, in addition to the introduction of platinum to the market, which was more hardwearing than traditional gold. It became fashionable for pieces to incorporate precision cut gemstones and diamonds; however, gemstones were still relatively hard to come by and finding perfect color matches for hundreds of melee stones proved challenging. Synthetic stones solved this problem as they offered an affordable way to guarantee color matched gems.
During the last century, researchers have developed a number of different ways to create these synthetic gem materials in the laboratory. Most of these methods fall into two major categories – melt or solution.
In melt processes, the chemical composition of the melt is the same as the composition of the resulting crystal. In solution processes, the solution has a different chemical composition than that of the resulting crystal. Solution methods are less common as they are more costly and time consuming, however some gemstones can only be made using a solution method.
Some of the main synthetic processes include:
Flame Fusion / Verneuil
The first commercially successful synthetic gems were created by the flame fusion process. This process involves dropping powdered chemicals through a high-temperature flame, where it melts and falls onto a rotating pedestal to produce a synthetic crystal. Today it remains the least expensive and most common way to make gems.
Crystal pulling emerged in the early 1900s. In this process, nutrients are melted and the synthetic crystal grows from a seed that is dipped into the melt, and then slowly pulled away from the melt as it grows. Gems created by pulling include alexandrite, chrysoberyl, corundum (sapphire and ruby), and garnet.
The flux-growth process uses flux - a solid material that, when melted, dissolves other materials in the same way that water dissolves sugar. As the dissolved chemical solution gradually cools, synthetic crystals form. Crystal growth can take up to a year, and the equipment is very expensive.
Like the flux process, the hydrothermal growth process is slow and expensive, but it’s the only method to successfully grow synthetic quartz. This process requires heat and pressure and imitates the conditions in the earth that result in the formation of natural gems.
In the 1970s, the development of the flame fusion process for creating corundum (resulting in stones such as ruby and sapphire) led to a revolution in the gemstone industry. This process allowed for the creation of high-quality synthetic gemstones that were virtually indistinguishable from natural stones, at a fraction of the cost. This led to a surge in popularity for synthetic gemstones, particularly in recent years in the form of lab-grown diamonds, which have become increasingly prevalent in the market.
In addition to lab-grown diamonds, other popular gemstones such as emeralds, rubies, and sapphires are now readily available as created stones and are often used in jewelry as an affordable alternative to their natural counterparts.
Overall, lab-grown gemstones have become increasingly popular in jewelry in recent decades thanks to advances in technology and the desire for affordable and sustainable alternatives to natural stones.