Identifying gold requires some experience. Briefly introduce some identification methods.

(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 "18K". If the fineness is lower than l0K, the K-gold seal number cannot be printed according to the 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.

Platinum identification

(1) visual inspection method: marking: each piece of jewelry should be engraved with the chemical composition seal, such as (pt 900) and (PT 750). All stamps that begin with "PT" are platinum ornaments: platinum is tin white, that is, white with gray and bright luster.

(2) Instrument detection: Hardness test: the hardness of platinum is 4-4.5 degrees, which is harder than gold and silver. It is scratched with a knife or glass, but it will not be scratched by nails. Density measurement: Platinum is extremely dense and feels heavy when weighed by hand. The density measured by hydrostatic pressure method should be 2 1.43g/cm. The melting point of platinum is as high as 178. Acid test when the color is unchanged: platinum is chemically stable and insoluble in ordinary acids. Draw platinum on the touchstone, drop hydrochloric acid, and try with hydrogen peroxide under the condition of unchanged wear marks: take a little platinum powder and put it into the hydrogen peroxide bottle, and hydrogen peroxide will immediately produce bubbles. After the reaction, platinum can still be used without any damage.

These are just simple identification methods, and the specific colors have to be tested by testing institutions.

If gold is good from the perspective of value preservation, it is hard currency and easy to realize; If it is simply used as an ornament, it depends on personal preference.