(1) Look at the color: The higher the purity of gold jewelry, the darker the color. In the absence of a gold medal, the general fineness can be determined according to the following colors (based on cyan gold). The so-called green gold is just silver in gold); The fineness of deep red yellow is above 95%, light red yellow is 90-95%, light yellow is 80-85%, blue yellow is 65-70%, blue white is only 50-60%, and yellow white is less than 50%. The so-called seven greens, eight yellows and nine reds can be used for reference.

(2) Balance weight: The specific gravity of gold is 19.32, which is heavier than silver, copper, lead, zinc, aluminum and other metals. Because the volume of gold is more than 40% heavier than that of silver, 1.2 times heavier than that of copper and 6. 1 times heavier than that of aluminum. Gold jewelry should feel heavy in your hand, while fake gold jewelry feels light and floating. This method is not suitable for gold ornaments with precious stones.

(3) Look at hardness: Pure gold is soft and low in hardness, and shallow marks can be drawn with nails, and tooth marks can be left after biting. Gold ornaments with high color are softer than those with low color, and the more copper they contain, the harder they are. Bending method can also be used to test hardness. Pure gold is soft and easy to bend, and the lower the purity, the more difficult it is to bend.

(4) Listen to the sound: When real gold with a purity of over 99% is thrown on the hard ground, it will beep, without rhythm and elasticity. Fake or low-quality gold sounds crisp and dull, generally making a "Dangdang" sound, with a lingering sound, and violently beating after landing.

(5) Burning with fire: Burn the jewelry to be identified with fire (do not melt and deform the jewelry), and observe the color change after cooling. If the surface is still golden, it is pure gold; If the color darkens or turns black to varying degrees, it is not pure gold. Generally, the lower the fineness, the thicker the color, and all of them turn black, indicating that they are fake gold ornaments.

(6) Look at the mark: domestic gold ornaments are purified and prepared according to international standards, and marked with marks, such as "24K" for "full red" or "pure gold"; 18K gold, marked with the words "18K". If the color is lower than Locke, the K-gold seal number cannot be printed according to regulations. Nowadays, criminals in the society often make fake brands and imitate stamps, and use rare gold, inferior gold and even brass as real gold. Therefore, the identification of gold ornaments should be based on the comprehensive judgment of samples to determine the authenticity and color.

(7) Touchstone method: select a black touchstone with delicate texture, draw traces on the touchstone with standard gold test pieces (for gold medals) with different gold contents, then scrape the gold jewelry sample to be identified on the same touchstone, add concentrated nitric acid to remove impurities, find out the traces left on the touchstone and compare them with the drawn gold test pieces, find out the same chromaticity as the jewelry sample, and compare the standard degree of the sample gold, that is, the accurate gold content of the gold jewelry sample to be tested.

(8) Chemical method: also known as reagent spot test method. Gold alone is insoluble in nitric acid, sulfuric acid and hydrochloric acid, while silver, copper and other components can react with nitric acid and be dissolved. Take samples of gold ornaments. If nitric acid is placed in a certain part, it will not change color if it is made of gold, and it will turn black if it is made of silver. In the case of copper products, bivalent copper salts will be generated and green bubbles will be emitted. Gold ornaments with gold content above 95% have little surface change when tested with nitric acid.