Detail of GB/T 16553-2017

Introduction of GB/T 16553-2017

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 16553-2010 Gems - Testing. The following main changes have been made with respect to 16553-2010 (the previous edition): ——The application scope is modified (see Clause 1). ——The references to terms and definitions in GB/T 16552 are added; the repeated terms and definitions of "phenomena", "heating", "diffusion", etc. are deleted; the terms and definitions of "color”, "colorless oiling” and "waxing” are deleted, those of "fluorescence" and "phosphorescence" are modified, and that of "inclusions" is added. (See Clause 3) ——The routine testing methods and special testing methods are combined as testing methods; wherein, the “UV fluorescence” is changed to “fluorescence observation”, and the “absorption spectrum” is incorporated into “UV-visible spectrum analysis”. (See 4.1) ——The principle and application scope of the testing methods such as infrared spectrum analysis and laser Raman spectrum analysis are modified; the operation steps in the testing methods such as infrared spectrum analysis, UV-visible spectrum analysis and laser Raman spectrum analysis are changed to the application in gems testing; luminescence spectrum analysis is added. (See 4.1) ——For the testing items, the “UV fluorescence” is changed to “fluorescence observation”, the absorption spectrum is deleted, and items such as infrared spectrum, UV-visible spectrum and Raman spectrum are added; the selection principle of the testing items is modified. (See 4.2) ——The infrared spectrum testing characteristics of each gem variety are added. (See Clause 5) ——The testing characteristics of varieties and subvarieties such as hauyne, sphalerite, balin stone, changhua stone, conch pearl and mammoth ivory are added, and those of turquoise are deleted. (See Clause 5) ——The enhancement and treatment types and testing characteristics of gems varieties such as diamond, emerald, spinel, turquoise, sugilite and amber are added and modified; the description of material properties as well as the testing characteristics of treatment methods such as dyeing, filling or impregnation and coating of gems varieties are regulated. (See Clause 5) ——The additions, deletions and medications are made accordingly in accordance with the modification of GB/T 16552 Gems - Nomenclature. This standard was proposed by the Ministry of Land Resources. This standard is under the jurisdiction of the National Technical Committee on Jewelry and Jade of Standardization Administration of China (SAC/TC 298). The previous editions of this standard are as follows: ——GB/T 16553-1996, GB/T 16553-2003 and GB/T 16553-2010. Gems - Testing 1 Scope This standard specifies the terms and definitions, testing methods, item selection and testing characters of gems. This standard is applicable to gems testing. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 16552 Gems - Nomenclature 3 Terms and definitions For the purpose of this standard, the terms and definitions specified in GB/T 16552 as well as the followings apply. 3.1 crystal solid with a lattice structure, of which, the internal particles are regularly arranged in a regular periodic arrangement in space 3.2 crystalline crystalline solid (crystal) 3.3 crystalline aggregate block composed of numerous crystallines Note: crystalline aggregate includes phanerocrystalline aggregate and cryptocrystalline aggregate. 3.4 non-crystalline solid of non-lattice structure, of which, the internal particles are irregularly arranged in space 3.5 crystal system classification reflecting the symmetry of the crystal, which is divided into seven crystal systems according to the symmetry degree: equiaxial system, hexagonal system, tetragonal system, trigonal system, orthorhombic system, monoclinic system, and triclinic system 3.6 crystal habit habit of certain mineral of tending to crystallize into a certain form under certain external conditions 3.7 crystal twinning regular formation of two or more of the same crystals according to certain symmetry rule Note: it is classified into contact crystal twinning, interpenetrant crystal twinning and ring crystal twinning according to the individual formation mode of crystal twinning. The contact crystal twinning is further classified into simple contact crystal twinning and polysynthetic crystal twinning. 3.8 twinning striation linear striation appearing on the crystal face, cleavage plane or gems cutting plane of crystal twinning joint surface 3.9 crystal face plane encircling the crystal surface, which is naturally formed during crystal growth 3.10 striation straight striation formed by a series of so-called adjacent faces on a crystal face, also called growth striation or combination striation 3.11 color band uneven distribution of internal color in a band (or block) shape Note: the original color band is a change in color depth or color due to changes in medium composition and growth environment during crystal growth. 3.12 optic character phenomena generated due to the action of material in the incidence and propagation directions of light, including such characters as the isotropy and anisotropy of material, axiality and positive/negative characters of anisotropic material 3.13 isotropic material material with optic character the same in all directions Note: the equiaxial-system and non-crystalline materials are isotropic. 3.14 anisotropic material material with optic character different in each direction Note: all materials other than equiaxial-system and non-crystalline materials are anisotropic. 3.15 optic indicatrix optical indicator indicating the relationship between the vibration direction of light wave and the corresponding refractive index when the light wave propagates in a crystal 3.16 uniaxial crystal crystal with only one special direction (one optical axis), which is free of birefringence when the incident light is parallel to this direction Note: the crystals of trigonal system, tetragonal system, and hexagonal system are uniaxial. 3.17 biaxial crystal crystal with two special directions (two optical axes), which is free of birefringence when the incident light is parallel to the two directions Note: the crystals of orthorhombic system, monoclinic system and triclinic system are biaxial. 3.18 optic orientation the spatial relationship between the principal axis of the optic indicatrix and the crystallographic axis of the crystal Note: the uniaxial crystal gemstone is of positive character when its ordinary light refractive index (No) is less than the extraordinary light refractive index (Ne), otherwise, it is of negative character. The three main refractive indexes of the biaxial crystal gemstone are represented by Ng, Nm, and Np as large, medium and small, respectively; where Ng-Nm>Nm-Np, such gemstone is of positive character, otherwise, it is of negative character. 3.19 refractive index ratio of the propagation speed of light in air (or vacuum) to that in gem material Note: the refractive index in gems test is the relative refractive index measured in air. 3.20 birefringence the maximum difference between two or three main refractive indexes in anisotropic material, also called double refraction 3.21 pleochroism phenomenon that a anisotropic colorful gemstone presents different colors due to the selective absorption of light waves in different crystal directions, which is classified into dichroism and trichroism 3.22 dichroism phenomenon that a uniaxial crystal colorful gemstone presents two different colors in two main vibration directions 3.23 trichroism phenomenon that a biaxial crystal colorful gemstone presents three different colors in different main vibration directions 3.24 absorption spectrum spectrum generated by the gem material by selectively absorbing the light of continuous spectrum on it 3.25 luster light reflection capability and characteristics of the surface of gem material Note: it is classified into metallic luster, submetallic luster, adamantine luster and vitreous luster according to the luster intensity; special lusters caused by the aggregate or surface characteristics include greasy luster, waxy luster, pearly luster, silky luster, etc. 3.26 transparency degree of light transmission of gem material Note: it may be classified into transparent, semitransparent, translucent, semitranslucent and opaque. 3.27 fluorescence phenomenon that the gems emit visible light under the illumination of excitation light source Note: it is classified into strong, medium, weak and none according to the light intensity. UV light is generally used as excitation source in gems testing. 3.28 phosphorescence phenomenon that the gems continue to shine in a short time after removing the excitation light source Note: UV light is generally used as excitation source in gems testing. 3.29 play-of-color phenomenon that colors generated due to light interference or diffraction by certain special structures of gems change with the light source or observation direction

Contents of GB/T 16553-2017

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Testing methods and item selection 4.1 Testing methods 4.2 Testing items and selection principle 5 Testing criteria 5.1 Natural gemstones 5.1.1 Diamond 5.1.2 Ruby 5.1.3 Sapphire 5.1.4 Chrysoberyl 5.1.5 Cat’s-eye 5.1.6 Alexandrite 5.1.7 Emerald 5.1.8 Aquamarine 5.1.9 Beryl 5.1.10 Tourmaline 5.1.11 Spinel 5.1.12 Zircon 5.1.13 Topaz 5.1.14 Peridot 5.1.15 Garnet 5.1.16 Rock Crystal 5.1.17 Fledspar 5.1.18 Scapolite 5.1.19 Kornerupine 5.1.20 Zoisite (tanzanite) 5.1.21 Epidote 5.1.22 Iolite 5.1.23 Sphene 5.1.24 Apatite 5.1.25 Pyroxene 5.1.26 Andalusite 5.1.27 Sillimanite 5.1.28 Kyanite 5.1.29 Apophyllite 5.1.30 Lazulite 5.1.31 Idocrase 5.1.32 Sinhalite 5.1.33 Taaffeite 5.1.34 Benitoite 5.1.35 Barite 5.1.36 Celestite 5.1.37 Calcite 5.1.38 Axinite 5.1.39 Cassiterite 5.1.40 Amblygonite 5.1.41 Dioptase 5.1.42 Euclase 5.1.43 Braziiianite 5.1.44 Danburite 5.1.45 Phenakite 5.1.46 Hauyne 5.1.47 Sphalerite 5.2 Natural gems 5.2.1 Feicui, Jadeite 5.2.2 Nephrite, Hetian Yu 5.2.3 Opal 5.2.4 Quartzite jade 5.2.5 Chalcedony (Agate/Jasper) 5.2.6 Silicified jade (Silicified Asbestos/Silicified Wood/Silicified Coral) 5.2.7 Serpentine 5.2.8 Dushan Yu 5.2.9 Charoite 5.2.10 Albite Jade 5.2.11 Rhodonite 5.2.12 Actinolite 5.2.13 Turquoise 5.2.14 Lapis Lazuli 5.2.15 Malachite 5.2.16 Chrysocolla 5.2.17 Prehnite. 5.2.18 Marble 5.2.19 Smithsonite. 5.2.20 Rhodochrosite 5.2.21 Dolomite 5.2.22 Fluorite. 5.2.23 Hydrogrossular 5.2.24 Talc 5.2.25 Datolite 5.2.26 Howlite 5.2.27 Sodalite 5.2.28 Hematite 5.2.29 Natural glass 5.2.30 Chicken-blood stone 5.2.31 Shoushan stone 5.2.32 Qingtian stone 5.2.33 Balin stone 5.2.34 Changhua stone 5.2.35 Brucite 5.2.36 Sugilite 5.2.37 Hemimorphite 5.2.38 Mica jade 5.2.39 Pectolite 5.2.40 Chlorite 5.3 Natural organic materials 5.3.1 Natural pearls 5.3.2 Cultured pearl (pearl) 5.3.3 Conch pearl 5.3.4 Coral 5.3.5 Amber 5.3.6 Jet 5.3.7 Ivory 5.3.8 Mammoth Ivory 5.3.9 Tortoise Shell 5.3.10 Shell 5.4 Manufactured products 5.4.1 Synthetic Diamond 5.4.2 Synthetic Ruby 5.4.3 Synthetic Sapphire 5.4.4 Synthetic Emerald 5.4.5 Synthetic Beryl 5.4.6 Synthetic Chrysoberyl 5.4.7 Synthetic Alexandrite 5.4.8 Synthetic Spinel 5.4.9 Synthetic Opal 5.4.10 Synthetic Quartz 5.4.11 Synthetic Rutile 5.4.12 Synthetic Cubic Zirconia 5.4.13 Synthetic Moissanite 5.4.14 Synthetic Jadeite 5.4.15 Yttrium Aluminium Garnet(YAG) 5.4.16 Gadolinium Gallium Garnet (GGG) 5.4.17 Strontium Titanate 5.4.18 Strontium Aluminate Borate 5.4.19 Plastic 5.4.20 Glass