One of the precious metals used by human beings is gold. It is not only used in ornaments but also in different purposes. It comes with different colors and levels of purity, according to which its price is decided. To identify its quality, purity, and level of finish, there are many processes available in the market. To get a deep knowledge of those testing processes let’s have a look one by one. You also need to be well aware of the scrap gold prices in London that will make you more advance in testing gold.
Surface Inspection
By closely observing and testing the surface of a piece of the gold element we can assure and make comments on its purity and significant character. This includes three stages or way of verification:
- Hallmark
- Fading along the edges
- Spot on surface
- Use of magnet
A gold piece will surely be marked with a certain kind of code on its surface. The code comprises of a short form of any category. Like a small stamp of “HGP” or “GF” signifies that the metal piece is gold plated or not pure gold. Similarly, a pure gold piece will be stamped with “24k” or sometimes different marking, indicating the purity and fineness of the gold piece. This kind of stamp or marking is referred to as hallmarks and they are mainly located inside the band of rings or near the clasp on necklaces.
However, it is also important to keep in mind that some markings can be faked. Therefore some big brands use a mark as only one of its many indicators of authenticity. The hallmark can be small which may need a magnifying glass to clearly see.
To look for faded edges you need to turn on a bright light or lamp, and then hold the gold piece close to the light. Slowly rotate and try to find any faded surface on the piece. If you find any such portion on the surface, then it’s likely to wear on plating. This indicates that the metal is not pure gold.
By the same process as above, if you find any white or red spots anywhere on the surface of the metal, it indicates that it’s not pure gold. The spots may be very tiny and small to observe in the naked eye. This is the reason why experts recommend examining under bright light with a magnifying glass.
Hold a magnet above the gold piece and slowly decrease the gap between the piece and magnet until it touches the piece. If you see that magnet attracts the metal piece or vice versa, then the metal piece is not pure gold. Pure gold will never draw or attract a magnet. But other metals such as nickel, brass, etc can easily attract a magnet.
Deep Inspection
This is the second process for inspection of pure gold and this includes the following ways:
- Hold the experimental metal object on a particular place or on a table. Use a dropper filled with white vinegar to put a few of its drops on the metal surface. If the drops change the color of metal, then it is not pure gold and vice versa.
- Hold the given object with your or with any metal holder. Wipe it across the black jeweler’s stone firmly and slowly. If the object leaves any gold colored mark on the stone then it ensures a pure gold. If the metal leaves no marking or lining on the stone then it is not pure or only gold plated. It should be carried out very carefully as it has a risk of damaging your jewelry.
- Rub your metal piece on a ceramic plate firmly and if it leaves the same gold marking, then it is pure gold and vice versa.
- Put some drops of makeup liquid foundation on a particular surface area of your hand. Wait until the foundation is dry. Now rub thoroughly against the foundation. A piece of pure gold will leave a line of the mark in the makeup and if you do not observe any such mark then it is another plated metal.
- You can also use an electronic gold tester machine and XRF machine to determine the originality of a gold machine that is available in the market.
- If nothing goes correct, you can consult any professional person. An assayer will perform a deep analysis of the metal. It may be a costlier way but will be worthwhile.
Acid Test
Buy an acid testing kit from a jewelry tool shop which is quite affordable if you purchase online. Inside the kit, there will be a number of needles with marking karat value on its one side. Each and every needle will be colored at the tip according to the gold color.
Using any of the tools makes a notch on the surface of a given metal piece until you find the deeper layers of the metal. Put a drop of acid by selecting the proper needle for the type of gold. Keep pushing the needle downwards until a drop goes into the pivot.
Now keep a close look on the pivots, the one you made earlier, and another where you just applied the acid. The acid will react to metal and change its color. If the metal turns into green, then the metal is not pure gold or gold plated.
According to the London Gold Centre, it is important to read the color guide and instructions thoroughly before performing such an experiment. It is also necessary to put on gloves and goggles during the acid test.
