There are at least six ways of investing in gold: Buying gold coins: This is the most popular way of investing in gold. Gold bullion coins are typically priced based on their weight; a premium is added to the gold spot price. Gold coins may be bought or sold over the counter in most Swiss banks. Buying gold bars: This is the most traditional way of investing in gold. 2. As filaments in making ion gauges, mass spectrographs, and photoflash lamps. 3. As electrical contact materials, due to its high resistance to arc corrosion and wear. 4. As catalysts for hydrogenation of fine chemicals, because of its high resistance to chemical poisoning from phosphorus, sulfur, and nitrogen. federal agency CDC reveal that exposure to platinum salts, on the short term, may cause nose, throat, and eye irritation. Long-term exposure to these compounds, on the other hand, may cause skin and respiratory allergies. Palladium: Palladium in bulk metallic form is completely inert. The same can't be said though of the metal in finely divided form, which can readily ignite in air. This makes it an extremely rare metal. Compared to gold, platinum is more precious, although its price is considered more volatile. One of the reasons for this is that its demand is driven by industrial uses or applications. For example, its price tends to be double that of gold's when world economy is stable, but significantly goes down in times of economic uncertainty. A third important factor that will qualify an element as a precious metal, as may be noted from the uses of gold and silver above, is that it should not be radioactive. Thus, the chemical elements actinium, polonium, and radium are not considered precious metals because they are highly radioactive. Compared to most other elements, precious metals are chemically less reactive, have higher melting points, and are more ductile - properties that make them ideal for many commercial and industrial applications. Once the base metals are heated at high temperatures, the gold (as well as the other precious metals that may be present) remains apart and the other non-precious metals react forming other compounds. Cupellation basically has two processes: large scale and small scale. Spectrometry: This method is best used to assay platinum bullion or stock.