GB/T 23885-2009Jadeite grading (English PDF)
翡翠分级
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Issued by
General Administration of Quality Supervision, Inspection and Quarantine; Standardization Administration of the PRC
Level / Type
National · Recommended
Issue date
June 1, 2009
Implementation date
March 1, 2010
Scope
GB/T 23885-2009 is the English-translated version of 翡翠分级.
China's national standard for grading jadeite. It specifies the terms and definitions, the grading of colour, transparency, texture and workmanship, and the comprehensive grading of jadeite. Jadeite is the most valuable gem material in the Chinese market and the hardest to grade, because unlike a diamond it is not a transparent single crystal judged on defined defects but a polycrystalline rock judged on qualities that had been transmitted as connoisseurship rather than as measurement. The value spans four or five orders of magnitude between ordinary material and imperial green, and it turns on properties that a buyer traditionally assessed by eye and by experience. This standard is the attempt to make them explicit. Colour is graded on hue, saturation and lightness rather than as a name, which matters because the green that carries the value is a narrow range and adjacent greens are worth a fraction. Transparency is graded because the same colour in translucent material and in opaque material are different products entirely. Texture is graded on the fineness and uniformity of the interlocking crystals, which is what produces the luminous quality the trade calls water and which cannot be improved. Workmanship is graded because jadeite is sold as finished pieces and the cutting either uses the material or wastes it. And the comprehensive grade combines them. Underlying all of it is the distinction the market rests on and which the accompanying identification standards enforce: natural jadeite, bleached and impregnated jadeite, and dyed jadeite are graded as different things, because the treatments that improve appearance are undetectable by eye and reduce the value enormously. Issued on 1 June 2009 and in force since 1 March 2010.
Document preview — GB/T 23885-2009
National Standard of the People's Republic of China
- ICS
- 39.060
- Classification
- D 59
Issued by: General Administration of Quality Supervision, Inspection and Quarantine; Standardization Administration of the PRC
Contents
- ForewordIII
- 1 Scope1
- 2 Terms and definitions1
- 3 Emerald (colorless) grade3
- 4 Emerald (green) grade5
- 5 Emerald (purple) and Jade (red - yellow) grade7
- 7 Emerald unevenness evaluation7
- 8 Emerald Technology Assessment8
- 9 Emerald 8 Quality8
- 10 Emerald grading certificate8
- Appendix A (normative) Methods of measurement --- Jade transparency spectral photometric method9
- Annex B (informative) emerald (green) color measurement method --- spectrophotometric color measurement method11
- Annex C (informative) emerald (green) color and shape distribution of13
- Annex D (informative) Emerald Technology Assessment14
- Annex E (informative) Emerald common internal and external features15
- References16
Foreword
The Standard Appendix A, Appendix B, Appendix C, Appendix D, Appendix E is an information appendix.
The standard proposed by the People's Republic of China Ministry of Land Resources.
This standard by the National Standardization Technical Committee jewelery.
This standard was drafted. Gems & Jewelry Management Center.
The main drafters. Zhang Beili, Wang Manjun, Ke Jie, Sun Fengmin, Zhang Hui, Zhang Jian, Ma Yang Wei, violence Wei, Guo Tao, Chen.
This standard is the first release.
1 Scope
This standard specifies a natural mosaic not polishing and grinding jade inlaid classification rules.
This standard applies to non-natural mosaic and inlaid polished polished jade.
2 Terms and definitions
The following terms and definitions apply to this standard.
Mainly composed of jadeite and jadeite or by the other Na, sodium calcium pyroxene (sodium chromium pyroxene, green pyroxene) consisting of a process value mineral collection
Body may contain small amounts of amphibole, feldspar, chromite and other minerals. Mohs hardness of 6.5 to 7, and density 3.34 (+ 0.06, -0.09) g/cm3, refractive
Rate 1.666 ~ 1.680 (± 0.008), measured 1.65 to 1.67 points.
2.1.1 Colorless or low color saturation emerald.
2.1.2
Main color is green hue, saturation and has a certain emerald.
2.1.3 The main color is purple hue, saturation and has a certain emerald.
2.1.4
Body color and a color of red - yellow, and has a certain saturation emerald.
From the color (colour), transparency (transparence), texture (texture), clarity (clarity) of the four-level plans were emerald
Points and evaluation of their processes (artsandcrafts).
From transparency, texture, clarity three aspects Emerald (colorless) were divided into levels, and evaluate its processes.
From the color, four of transparency, texture, clarity emerald (green) were divided into levels, and evaluate its processes.
From four color, transparency, texture, clarity emerald (purple) and Jade (red - yellow) level is divided, and its technology into Evaluated.
Remaining clauses in the full document
- 3 Emerald (colorless) grade
- 4 Emerald (green) grade
- 5 Emerald (purple) and Jade (red - yellow) grade
- 7 Emerald unevenness evaluation
- 8 Emerald Technology Assessment
- 9 Emerald 8 Quality
- 10 Emerald grading certificate
......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 19 pages — is available in the English PDF.
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