As a non-destructive assay method, XRF can identify various elements in a substance (in fact, even in powder and liquid ones) within a few minutes. One of the most important aspects in any of the assay methods pertains to the accurate determination of the composition of a substance at various points in the process. As a filter in X-ray systems (such as mammography). 5. In surfaces of high quality pens (because of its high mechanical and chemical resistance). Obviously because of its extremely high price, rhodium signifies wealth. In some cases, it has been used in awards or recognitions, such as when the Guinness Book of World Records handed out a rhodium-plated disc to Paul McCartney in 1979, in recognition of his being the all-time best-selling recording artist and songwriter in history. They are more ductile or softer than most other elements. They are less reactive compared with other elements. They have excellent luster. They have higher melting points compared with other metals. The high-ductility property of gold and silver means they can be easily damaged as coins for circulation. 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. While bullion coins are issued as legal tender, with nominal values assigned to them on minting, such face values are far below the commodity value of the metals themselves. Here's an example: Most of the gold coins issued by national governments, particularly those with currency values of between 10 and 100 U. Gold Standard: Definition And The Three Distinct Kinds The gold standard is defined in many different reference materials as a monetary system in which the unit of currency used is a fixed quantity or weight of gold. Under this system, all forms of money, including notes and bank deposits, were freely converted into gold at the fixed price.