Not to be trapped in the first place not buy a gold watch in questionable places, and making the purchase, take care that the seller gave you all the necessary documents in case of return of defective goods.
Because a gold watch for a long time are in contact with the surface of the skin, then it should not show any irritations. Gold is only in very rare cases can cause an allergic reaction, so if the skin irritation, it means there is reason to doubt the authenticity of the gold.
This metal is extremely resistant to attack by acids. Dissolving gold may only "Aqua Regia" - a concentrated mixture of nitric and hydrochloric acids. Can test the quality of gold by rubbing the product in hand for about a minute. At low levels of precious metal you will have a dark blue trace.
There is one easy way to determine the quality of gold jewelry is to put it four hours on a piece of fresh bread. A high carat gold will not change its type, and the forgery will be covered with characteristic dark spots.
You can use home chemistry, which is in almost any home – vinegar and iodine. As in the case of "Aqua Regia" substandard products in contact with them darken.
Another way to test the quality of gold products will want to use a few, but, nevertheless, it is quite effective. This should hold it on the surface of the unfired ceramic tile, while real gold will leave a gold line, and after the fake will remain gray or black streak.