GB 11887-2002.Jewellery-Fineness of precious metal alloys and designatiion. 4.2足金 首饰因使用需要,其配件含金量不得低于...

GB 11887-2012.Jewelery-Fineness of precious metal alloys and designation. GB 11887规定了首饰中贵金属的纯度范围”、印记...

GB 11887-2012.Jewellery-Fineness of precious metal alloys and designation. GB 11887规定了首饰中贵金属的纯度范围”、印...