![]() ![]() These analyzers, however, are not portable, and in general, require a higher level of operation skills than those of portable XRF analyzers. Larger, bench top analyzers provide unprecedented performance in terms of x-ray tube power, beam collimation, accuracy, and sample positioning. There are laboratory methods with larger and expensive machines, but you must do extensive sample preparation. Brittanica defines cupellation as a “separation of gold or silver from impurities by melting the impure metal in a cupel (a flat, porous dish made of a refractory, or high-temperature-resistant, material) and then directing a blast of hot air on it in a special furnace.” The problem with this method, however, is that it is a destructive method because you must melt the piece in order to determine the gold concentration. Fire assay, sometimes known as cupellation, is considered the most precise method. ![]() These testers use the principle of electrical conductivity to determine the gold concentration but have low accuracy. In this infographic, we’ve outlined eight reasons one should not use acid to test jewelry. Not only that, you’re using hazardous acids that can burn your fingers. This method is often used, but it’s not very accurate. Scratch and Acid Test: The first method is the scratch and acid test, in which one uses a touch stone to scratch the piece of jewelry or metal, and then you pour different types of acid to determine the karats.There are five main methods for analyzing precious metals. Pawnbrokers, cash-for-gold operations, and jewelry stores who buy and sell gold and other precious metals must ensure that they know the exact composition of pieces not only so they can value the pieces correctly in the store, but so they don’t run into the issues of overpaying the customer, or getting underpaid by the foundry if the pieces will be melted down and recycled. We’ve previously written about the four primary precious metals - gold, silver, platinum, and palladium - and how it is important to verify the content of precious metals pieces in order to assess the correct value. ![]()
0 Comments
Leave a Reply. |