GB/T 32862-2016Sapphire grading (English PDF)

Foreword

This standard is drafted in accordance with the rules given in GB/T 1.1-2009. This standard by the National Jade and Jade Standardization Technical Committee (SAC/TC298) centralized. This standard is drafted by the National Jade and Jade Quality Supervision and Inspection Center. The main drafters of this standard. Zhang Jian, violent Wei, Lu Tai Jin, Chen Hua, Ke Jie, Bi Lijun. Sapphire grading

1 Scope

China's national standard for grading sapphire. It specifies the grading rules for natural, untreated or heat-treated, unmounted faceted polished sapphires, covering the identification of sapphire, the colour grading, the clarity grading, the brilliance grading, the treatment of heat treatment, the grading requirements, the cut, the mass and the grading certificate, with informative annexes on common internal and external features, the observation diagrams, the types of heat treatment and the common cuts and their proportions. Diamond has had a grading system for decades and coloured stones have not, and the difference is not arbitrary. Diamond is graded on the absence of things - the absence of colour, the absence of inclusions - and absence is easy to scale. Sapphire is graded on the presence of a colour, and the market's judgement of a colour is not a single axis: the most valuable blue is a particular combination of hue, tone and saturation, and stones that are darker, lighter, greyer or more violet fall away from it in several directions at once. Building a grading scale therefore requires deciding where the reference point is and how distance from it is measured, which is a commercial judgement dressed as a technical one. This standard makes those decisions for the Chinese market: it defines the colour grades for blue sapphire, allows other colours to use the same framework apart from colour itself, and it addresses heat treatment explicitly - almost all sapphire on the market has been heated, and disclosing it is what separates a graded stone from an undisclosed one. Issued on 29 August 2016 and in force since 1 March 2017.

This standard specifies the classification rules for natural, unprocessed or heat-treated, inlaid faceted polished sapphires. This standard applies to the natural non-optimized treatment or heat treatment of the mosaic facet grinding polishing sapphire grading, mosaic facet grinding System graded sapphire grading can refer to the implementation of this standard. This standard applies to blue sapphire grading, other colors sapphire grading in addition to color can refer to the implementation of this standard.

2 Normative reference documents

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this article Pieces. For undated references, the latest edition (including all modifications) applies to this document.

GB/T 16552 Name of jewelery and jade

GB/T 16553 Jewelery Identification

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 Sapphire sapphire Corundum gem in addition to ruby other than the color of the gem of the collectively, the chemical composition of Al2O3, containing Fe, Ti, V, Mn and other elements. Mohs hardness of 9, the refractive index of 1.762 ~ 1.770 (0.009, -0.005), birefringence value of 0.008 ~ 0.010, density 4.00 (0.10, -0.05) g/cm3.

3.1.1 Blue sapphire bluesapphire The main color tone is blue sapphire.

3.1.2 Powder - orange sapphire pink-orangesapphire The main color tone is pink - orange sapphire.

3.1.3 Pink Sapphire Pinksapphire The main color tone is pink sapphire.

3.1.4 Yellow Sapphire yelowsapphire The main color tone is yellow sapphire.

3.1.5 Purple sapphire purplesapphire The main color tone is purple sapphire.