Jinguojian Gold, Silver and Jewelry Inspection and Testing Center is reliable.

(Shenzhen) Gold and Silver Jewelry Quality Testing Center Co., Ltd. was established on July 14, 2065438, with its registered place at Yutian Community 1 Building1KLOC-0/,Cuizhu Street, Luohu District, Shenzhen, and its legal representative is Huang. Business scope includes general business items: quality inspection of gold, silver, jewelry, jade, diamonds, wood and precious metals.

The main fields cover nondestructive testing of precious metals, chemical composition analysis, jewelry and jade identification, diamond classification, jade classification and so on. The inspection certificate and inspection report issued are authoritative and legally effective.

The center has a strong technical force and has a high-quality management team composed of experts, engineers and doctors with rich experience and comprehensive professional knowledge in precious metal analysis, jewelry and jade appraisal, diamond appraisal and grading, and jewelry inspection.

The methods to test the authenticity of gold include color, mark, hardness, sound, weight, hardness test, porcelain scraping, nitric acid test, fire test and magnet test.

1, look at the color

According to the different luster and color of gold, pure gold, k gold, real gold and fake gold can be roughly distinguished. The old jargon handed down from pawn shops is "seven green, eight yellow, nine five red, yellow and white with gray and half gold", which is used to describe the purity of gold. The purity of blue and white color is not high, and the purity of red and yellow color is high.

2. Look at this sign

According to the regulations, domestic gold ornaments must be stamped with steel seals. 24K indicates that the purity is above 99.6%, and 18K indicates that the purity is above 75%.

Step 3 look at the hardness

When high-quality gold is carved with pins or nails, it will leave traces. More than 97% of colored gold jewelry is folded two or three times, and wrinkles appear at the bend, also known as fish scales; About 95% of the color of gold jewelry is hard when bending, and the scales are not obvious.

About 90% of gold ornaments are hard when bending, and there are no fish scales; Gold jewelry with many impurities will break after two or three bends; If it is made of gold, it will break when bent, and there are obvious sand grains on the cross section.

4. Listen to the sound

Real gold with a purity of more than 99% will beep when thrown on the hard ground, which is disorganized and elastic. Fake or low-quality gold sounds crisp and dull, generally making a "Dangdang" sound, with a lingering sound, and violently beating after landing.

Step 5 consider

The specific gravity of gold is 19.3g/cm3, and the fineness is closely related to the specific gravity. When the specific gravity is close to 19.3, the content of pure gold is higher. Weigh it by hand to see if it is commensurate with its size. Large and light shapes may be adulterated.

But generally, if you hold it in your hand, you can feel that it is real gold jewelry when you feel a little heavier, indicating that the gold body is small and heavy. Beware of silly light ornaments and carefully distinguish whether they are fakes or semi-fakes.