Chinese Synthetics: The Anonymous Crowd

Market-driven crystal growers in China produce a wide variety of synthetic gems. But they’re avoiding “luxury” synthetic gems – for now

Most of us know that many products are manufactured in China very inexpensively. However, few in the trade know China produces large numbers of synthetic gems.

Except through an occasional mention in a trade magazine or technical journal, it’s hard to fathom the quality and quantity of China’s synthetic gem production. Perhaps it’s because none of the gems grown in China bears a recognizable name, unlike the “Chathams” from the U.S. or the “Birons” from Australia. Maybe then it’s appropriate to call this production the anonymous crowd.

Scientists have long known that China grows crystals and that some of their colleagues there are among the best in the world. In fact, some high-quality optical crystals are produced industrially only in China. And in the past two decades, some crystal growth conferences in China included entire sessions dedicated to crystals for jewelry. Why, then, do we know so little about Chinese synthetic gems? Are the Chinese growing anything that could impact the world’s jewelry market?

Capitalist enterprise: When entering the Chinese territory in Guilin, a visitor sees ads for a new golf club, western liquor and cigarettes. Capitalist enterprise rather than communist doctrine seems to be the order of the day.

The same applies to synthetic gems. Crystal growing institutions appear on the surface to operate in an independent fashion. The industry is represented by the Research Institute of Synthetic Crystals (RISC), which was created near Beijing in the 1960s mostly for military purposes.

The growth of gem crystals at RISC benefited from experience gained in the research and development of laser crystals, refractories and other non-gemological materials. Today, this very large laboratory perfects growth methods for various gem materials (among many other products) and then “exports” them to more than 200 production sites throughout China.

Smaller, apparently fairly independent units are found in various institutes and universities around the country. Some of them even started synthetic gem programs on their own, often driven by the need for cash to run a laboratory. Two such laboratories are found in Guilin (producing hydrothermal synthetic emerald) and Guangzhou, (producing synthetic quartz of various colors, including amethyst).

Market-driven: Chinese crystal- growing institutions are interested in crystals with large markets and high profit margins. They seek to export crystals in exchange for hard currencies. If the price goes down too much, as that of synthetic amethyst has in recent years, the growers stop production and concentrate on something more lucrative.

Rather than produce whatever they like, the Chinese growers listen carefully to customers. If they’ve developed a superb method to growth synthetic amethyst but a customer wants green quartz, for example, they gladly switch to green quartz. These are typical market-driven attitudes of capitalism.

Some Chinese crystal growing institutions regard the synthetic gem market as too small to be lucrative. However, a number of large and small laboratories are involved in it. With little exception, these labs have not entered the luxury synthetic market. They tend to produce large amounts of relatively inexpensive synthetics and imitations even if they have the talent to grow more sophisticated products.

What they produce: Chinese crystal growers offer a variety of corundums. Flame-fusion synthetic corundum comes in all the classical colors. Synthetic rubies in various shades of red, synthetic blue sapphires and “alexandrite-like” color-change synthetic sapphires are available. They also produce the large bright green and orange cats-eye sapphires found in jewelry and tourist shops all over China. A small portion of the synthetic sapphire is grown using Czochralski pulling, most notably pink titanium-doped sapphire produced in Shanghai. We also saw flux synthetic rubies, a byproduct of laser research at RISC in the 1960s, but they’re not available commercially.

Little synthetic beryl comes out of China, with the notable exception of Guibao emerald. This hydrothermal synthetic emerald is the only example we know of Chinese “luxury synthetics” (even if it is little known by western gemologists at the moment). It’s also the only Chinese synthetic with a name (a contraction of Guilin, the town where it originates, and the Chinese word for gem).

Guibao emerald is grown at the Research Institute of Geology for Mineral Resources using a fairly small hydrothermal apparatus, less than 0.5mm long. To obtain larger stones than this small apparatus would normally allow, scientists developed an ingenious technique by which they saw off the central colorless seed after the first growth stage and use both sides of the synthetic emerald growth as seeds for the second growth stage. This results in a crystal of solid synthetic emerald without a central colorless seed. The resulting gems can be faceted in the entire crystal thickness instead of in less than half, as with other hydrothermal beryls produced around the world.

Such technical resourcefulness is what has made Chinese crystal growers famous. It also offers an insight into what China could achieve with luxury synthetics if it ever decides to market them.

Other products include synthetic spinel in red, cobalt blue, pale blue, greenish yellow and a number of other tints. Czochralski-pulled synthetic alexandrite is grown in a couple of laboratories. However, concern about the toxicity of the beryllium oxide entering in the recipe for this crystal has slowed its production.

Perhaps China’s best known synthetic gem is quartz. Up to 100 laboratories reportedly produced synthetic quartz for industrial use at one time. But overproduction led many institutions to abandon this synthesis or turn to products they could sell to the jewelry industry.

China produces a large quantity of synthetic amethyst (about six laboratories are involved). The Guangzhou Institute of Geochemistry in Guang-zhou in southern China is one of the labs that produces and exports synthetic amethyst. At Guangzhou, nearly 10-ft.-high autoclaves (a far cry from the small ones used in Guilin) yield hand-size crystals in many colors: light and dark amethyst, two tones of citrine, smoky, green, cobalt-blue and colorless. The crystal growers’ skill is evident in amethyst crystals that are virtually free of the parasitic color zoning due to twinning found in most other productions.

Colorless and colored chunks of cubic zirconia up to a couple of inches also are manufactured in China. Scientists at RISC are proud of their green and blue CZ, which they say is colored by intrinsic defects instead of rare earth elements, as are other blue and green CZs. They produce only one unusual kind of CZ for jewelry applications – black polycrystalline zirconia used in watch faces, bands and other parts.

China also produces much synthetic diamond, but production is geared toward grit and none of it is gem quality. Techniques range from very basic to cutting-edge. Three years ago, RISC scientists tried the split-sphere technology (which the Russians have used to produce gem-quality diamonds). But they seem to have no interest in growing gem-quality synthetic diamonds and feel their own technology is best to achieve the high-quality grit they want to produce.

The future: Should we worry about Chinese synthetic gems? Those that are exported today pose no gemological identification problem (for a trained gemologist, that is). Unlike some recent Russian synthetics, most are variations of products manufactured in other parts of the world.

Nevertheless, two factors could be important in the future. First, low labor costs could lead to reduced prices for some products, which then could become more common at the low-end of the market. This already has happened with synthetic amethyst and could affect other gems.

Second, highly talented Chinese growers could become interested in producing luxury synthetics that could be hard to detect.

For the moment, however, it appears most likely we’ll continue to see the anonymous crowd of Chinese synthetics set in jewelry from around the world.

– Dr. Emmanuel Fritsch, a former research scientist at the Gemological Institute of America, now teaches at the University of Nantes in France.