Fake gold bar

Tungsten weighs almost as much as gold, but costs much cheaper, and fraudsters take advantage of this masterfully. Bought a real gold bar with a serial number and the document, and then performed a difficult job for gouging the inside of the ingot, the void is filled with tungsten and masked. The other day a fake bullion for which the buyer has paid 18 thousand dollars found in Manhattan. And how many of them still kept under the guise of real gold?