GB/T 32863-2016Ruby 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. The drafting of the standard units. the National Jade Jade Quality Supervision and Inspection Center, Chow Tai Fook Jewelery Bank (Shenzhen) Co., Ltd., Shenzhen City in the Thai precious stones Limited. The main drafters of this standard. storm Wei, Zheng Mingzhi, Zhao Feng, Wang Manjun, Ma Yangwei, Ke Jie, Bi Lijun. Ruby grading

1 Scope

China's national standard for grading ruby. It specifies the grading rules for natural, untreated or heat-treated, unmounted faceted polished rubies, covering the identification of ruby, 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 the common internal and external features, the observation diagrams, the types of heat treatment, and the common cuts and their proportions. Ruby and sapphire are the same mineral. Both are corundum, aluminium oxide, and what separates them is which trace element coloured the crystal: chromium gives red and the stone is called ruby, everything else is sapphire. That is why this standard and the sapphire grading standard were issued on the same day, share a structure and differ only where the material differs - and where it differs, it differs sharply. Chromium does something in corundum that no other colouring element does: it fluoresces. A ruby placed in daylight absorbs ultraviolet and emits red, so the stone returns more red light than fell on it, and the colour appears to come from inside rather than off the surface. That is the quality the trade has always paid for and the reason a fine ruby outprices a diamond of the same weight. It also means the grading conditions have to be controlled with more care than for other stones, since the fluorescence responds to the ultraviolet content of the light being used. Clarity is graded on a scale suited to a material in which inclusions are the norm, and heat treatment, which nearly every ruby on the market has had, is addressed and disclosed. Issued on 29 August 2016 and in force since 1 March 2017.

This standard specifies the grading rules for natural, unprocessed or heat-treated, inlaid faceted polished rubies. This standard is applicable to natural non-optimized or heat-treated non-inlaid faceted polished ruby grades, Polishing rubies can be performed with reference to this document.

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 Ruby ruby Mainly from the Cr ion color, the color is medium to dark red corners of the corundum gem, the chemical composition of Al2O3, can contain 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

0.05 g/cm3.

3.2 From the color, clarity, fire color, quality and other aspects of the ruby level division.

3.3 Color grading Using colorimetric method, in the prescribed environment for the color of the ruby level division.

3.3.1 Hue hue Said ruby red, purple, orange and other color characteristics.

3.3.2 Chroma Ruby color saturation and lightness after the combination of a color show the effect of a color.

3.3.3 Ruby color grading standard sample rubycolor revisedansterset An elliptical faceted ruby sample with a calibrated hue category and a chroma level, in turn, represents a different saturation level.

3.3.4 Color card A standard color card that represents a certain color.

Note. In this document you can use "theMunselBookofColor-GlossyColection" for color matching.