Expanded knowledge,
A, the National Silicon Materials Deep Processing Product Quality Supervision and Inspection Center (hereinafter referred to as "National Silicon Inspection") is the State Administration of Quality Supervision and Inspection approved by the country's first professional engaged in the quality of silicone materials and their deep-processing products inspection of the national inspection centers located in the New Asia-Europe Continental Bridge, the eastern bridgehead -- Lianyungang, the laboratory is located in the New Asia-Europe Continental Bridge. --Lianyungang, the laboratory is located in the Oriental quartz center, the capital of China's crystal, China's silicon materials industry base - Donghai County.
The center is authorized by the Jiangsu Provincial Bureau of Quality and Technical Supervision statutory inspection agency, and accredited by the China National Accreditation Service for Conformity Assessment. Undertake the supervision of gold and silver, diamonds, precious stones and other product quality, testing, identification tasks, to provide users with various types of gold and silver jewelry products (including gold, platinum, silver and other precious metal jewelry as well as diamonds, rubies and sapphires, emeralds, crystals and other more than a hundred kinds of gemstones, jade and stone products) of quality inspection services.
Three, the site's existing laboratory area of 350 square meters, equipped with professional quality inspection of jewelry, with Nicolet 6700 Fourier Transform Infrared Spectrometer, GIA microscopes, diamond cut ratio meter, fiber optic spectroscopy, cathodoluminescence of gemstones, diamond thermal conductivity, desktop spectroscope and precious metals detector and other complete sets of advanced gold and silver jewelry testing equipment.
1, look at the mark: gold jewelry sold in international or domestic official stores, generally played with the gold content of the seal words, such as: 24K, 18K, 14K or 999 (i.e., 99.9% gold, equivalent to 24K), 750, 583, etc., with such a seal, generally speaking, is the real deal.
2, weighing: real gold in the hand should feel heavy, fake gold feels lighter, because the density of gold is greater than silver, copper, lead, iron and other metals, double to one and a half times about.
3, listen to the sound: the gold thrown on the hard ground, landing to listen to its ringing, real gold issued by the sound of low boring, thick, heavy, generally porpoise ringing, and the sound of the sound, fake gold sound brittle and no sense of dullness, generally when when the ringing, and the sound of the sound, and then again, the real gold when landing on the ground jumped no more than three times, not as intense as the fake gold to get.
4, test hardness: such as real gold, with handcrafted bending should feel softer, fake gold is hard.
5, with fire: put the jewelry in the fire grill, to be slightly red jewelry after taking out after cooling, pure gold jewelry is still color like new, K gold jewelry is a kind of smoke gray oxidation layer on the surface, and the lower the color of the more black, and the gold-plated jewelry by fire, the plating that will not disappear, the material on the original shape of it.
6, with a touchstone: choose a delicate texture of black touchstone, with varying gold content (known) of the gold test piece in the touchstone traces, and then the determination of the jewelry in the same touchstone traces, drops of concentrated nitric acid to remove debris (other than gold other than metal), and the sample traces of the scratch comparison, the same color as the traces of the same color, that is, the determination of the accurate content of the jewelry required gold.
7, measured by proxy:
(1) specific gravity method: this method uses analytical balance as a measuring instrument, according to the different weights of the jewelry in the air and pure water, by Archimedes' law to calculate the specific gravity and color, the specific gravity = weight in the air ÷ (the weight in the air minus the weight in pure water).
(2) x-ray fluorescence spectrometry; this method irradiates the jewelry with a beam of x-rays emitted by a computer-controlled precision instrument (x-ray fluorescence spectrometry generation), and then the computer calculates the coloring of the gold jewelry and the content of the impurity elements according to the recorded x-ray spectrum and intensity.