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CHINA ‘S LAB STANDARDS

Based on modern gemological knowledge, industry standards were created to standardize the gem and jewelry trade and protect consumers. Over the past 30 years, China formed a series of lab standards based on both Western examples and research by Chinese gemologists.

The three most important are the Jewelry Industry Nomenclature Standard (GB/T 16552-2010), the Gem Identification Standard (GB/T 16553-2010), and the Diamond Grading Standard (GB/T 16554-2010). These standards apply to all labs across the country. They were first published in 1996, and updated versions were issued in 2010 and applied to lab work effective February 2011 (“2010 edition of the three…,” 2011). In addition, there are standards for precious metals.

CHINA ‘S LAB STANDARDS

The value of green jadeite has risen tremendously in China, and differences in qualities or grades can make large differences in price.

As the largest jadeite consumer in the world, China has sought a national standard on jadeite grading for years. It is a very difficult process, because jadeite has a wide range of appearances, including transparency, color zoning, and texture. Therefore, every piece is unique and evaluated largely on personal experience using trade jargon. In 2009, the General Administration of Quality Supervision, Inspection and Quarantine and the Standardization Administration published a national jadeite grading standard, GB/T 23885-2009. This standard mainly deals with green jadeite (figure 24), but it can also be applied to transparent, lavender, and red-brown material. The four factors evaluated are color, transparency, texture, and clarity. Gemologists may also comment on the craftsmanship of a particular piece on the certificate. The current standard uses letters to represent different grades while also using the corresponding trade jargon, so that consumers and dealers alike can easily connect the lab report with their goods. The establishment of this standard was supported by both the NGTC lab and high-end jadeite dealers.
China is also the world’s largest cultured pearl producer. In 2002, a grading standard (GB/T 18781-2002) was published regulating the terminology, grading factors, analysis methods, and product labeling for both saltwater and freshwater cultured pearls.

Some other colored stone varieties have a huge market in China, namely ruby, sapphire, rubellite, and more recently tanzanite. Consumers and gemologists expect more national standards to be issued and applied to identification and evaluation so they will be better guided in purchasing and certifying these gems.

THE SOURCE:

GIA

DIAMOND AND SILICON DISCS
IDENTIFYING OF NATURAL JADE FROM SYNTHETIC
IDENTIFYING OF NATURAL JADE FORM SYNTHETIC
SYNTHETIC GEM MATERIALS
SYNTHETIC GEM MATERIALS
GEM CUTTING DISC
AQUAMARINE
AGATE TREE
JADE AND OTHER GEM STONES
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