The Standard Methods for Testing Fei Cui for Hong Kong was funded and commissioned by the Hong Kong Council of Testing and Certification (HKCTC) under the Innovation and Technology Commission. It was formulated by the Gemmological Association of Hong Kong (GAHK) and executed, coordinated and supported administratively by the Hong Kong Productivity Council. The content was formulated by the working group of GAHK in five years’ time. It has been confirmed by the Panel on Promoting Testing and Certification Services in Jewellery Trade under the HKCTC and was launched on 4 March 2016 during the Hong Kong International Jewellery Show.
The standard lists 13 standard methods regarding the shape and cut, dimensions, weight, transparency, colour and distribution, polariscope examination, refractive index, specific gravity, fluorescence, Chelsea colour filter examination, spectroscopic examination, magnification examination and infrared spectrum examination. Hong Kong Jewellery speaks to the GAHK working group to find out more about the preparation process, details and significance of the standard.
HKJM: Hong Kong Jewellery
GAHK: GAHK working group
HKJM: How could this standard benefit the trade? What advantages does it have over existing testing methods or standards?
GAHK: In the past science and technology was less developed. Testing of fei cui depends largely on regular instruments. Previous understanding of jade was influenced by French mineralogist Augustin Alexis Damour’s sample study over a hundred years ago which divided jade into jadeite and nephrite. Jadeite thus came to be used as a synonym of fei cui.
After nearly 30 years of research, now we understand that fei cui is a polycrystalline aggregate, which is composed solely, or principally of jadeite, omphacite and kosmochlor. Other secondary minerals may also be present. As the data gathered from omphacite and jadeite in regular instrument testing overlaps, it is possible to mistake omphacite jade as jadeite jade.
Nowadays, most testing laboratories are equipped with hi-tech instruments so there is no difficulty in identifying different types of fei cui. There had been cases where materials previously mistaken to be jadeite jade were found to be omphacite jade. If such omphacite jade are mistaken as jadeite jade but generates a different result in international laboratories, it will cause a lot of problems. By adopting the ‘natural fei cui’ as the standard of testing we can solve problems like this. It is because in the Standard Methods for Testing Fei Cui for Hong Kong, the definition of fei cui contains jadeite jade, omphacite jade and kosmochlor jade, which fully complies with the regulations of the Trade Descriptions Ordinance in Hong Kong. Therefore, focusing on whether the material is natural fei cui or not in the conclusion could best protect the interests of laboratories, the trade and consumers.
HKJM: What challenges did the working group encounter when formulating this standard?
GAHK: The challenges mostly come from the condition and limits of the local business environment. Apart from standardising the testing methods to fulfill international ISO requirements, we also have to decide what instruments and methods to include in the standard. It is because we have to consider whether the gemologists and practitioners of local laboratories could master those techniques. Besides, operability and costs of the tests are important because local laboratories charge far lower fees for issuing certificates than their international counterparts. Furthermore, local customers often expect laboratories to issue certificates within a short period of time. Therefore, we have to consider these limitations facing the industry.
Also, during the process of formulation, we have to fulfill the needs of stakeholders including HKCTC, the Hong Kong Customs and Excise Department, the local fei cui industry, academic institutions, research industry and the Consumer Council. For example, the standard cannot violate the Trade Descriptions Ordinance. Regarding academic research, the local community and the National Gemstone Testing Center (NGTC) of China have acknowledged this standard. Facing overseas academia, as we cannot change their existing definitions of jadeite, omphacite and kosmochlor, we have to present to them our research findings that the three minerals coexist in fei cui, so that they would accept the use of the term ‘fei cui’.
HKJM: As this standard is specifically for Hong Kong, will it cause confusion in other areas such as mainland China or Myanmar?
GAHK: Although Myanmar is a major source of rough fei cui, it does not have a set of widely-accepted testing methods. The definition of fei cui contained in the Guobiao standards - the Chinese national standards is generalised while our standard is narrower. These two standards complement one another without contradiction. As the name ‘fei cui’ is adopted in both mainland China and Hong Kong, it can facilitate trade.
Both the standards of Hong Kong and mainland China belong to regional standards. Overall, regional standards are linked to international standards. If a regional standard is widely accepted and adopted in different regions, it can become an international standard though this is a slow process as it involves the understanding, mutual communication and tolerance of different stakeholders. We are also working towards this goal.
Internationally, GAHK has explained and promoted this testing standard at numerous international gemmological conferences such as the Gem and Jewelry Institute of Thailand (GIT), Gemstone Industry Laboratory Conference (GILC) and International Colored Gemstone Association (ICA) conferences. This standard was accepted by several overseas gemmologists who wish we could launch it as soon as possible. In the future GAHK will continue to promote it.
HKJM: Regarding nomenclature, how are 'jade' and ‘fei cui’ related?
GAHK: ‘Jade’ has multiple meanings in Chinese culture, which includes fei cui, suet jade and others. In the past, the English term ‘jade’ referred to jadeite and nephrite. ‘Jadeite’ is only a member of the fei cui family, so it is too broad to be described as ‘fei cui’. Fei cui is just a member of jade, so ‘jade’ does not accurately refer to fei cui.
HKJM: Do the three fei cui members (jadeite jade / omphacite jade / kosmochlor jade) command different market prices?
GAHK: The assessment of the price of fei cui depends on its transparency, grain size, colour, clarity, size (volume) and craftsmanship other than its mineral components. Therefore, certificate descriptions do not need to specify the type of minerals but whether it is natural fei cui. Nevertheless, the problem of whether it is natural and whether it has been treated occurs to all members of the fei cui family, so it requires relevant observation and determination in the testing.
HKJM: Why are tests for lustre and hardness not included in this standard?
GAHK: Factors such as the type of fei cui and polishing treatment will result in different lustre. As there is no instrument but only subjective observation to measure lustre, it is not included in the standard. The measurement of hardness involves destructive tests so, again, it is not included in the standard.
HKJM: Does the standard apply to fei cui in colours other than black, white and colourless?
GAHK: For the identification of fei cui in purple, yellow and brown, colour determination mainly depends on subjective observation instead of using instrument and data analysis. Therefore, it cannot be included in the standard.
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