Three Methods Of Assay For Raw Precious Metals Items of jewelry or art made of precious metals are hallmarked based on specific requirements either of the country of import or the place of manufacture. Such items, particularly those made of silver, gold, or platinum, are struck with an official mark (or series of marks), which guarantees fineness or purity of the metal used. high-temperature superalloys (used in making the turbine blades in jet engines); 4. fountain pen nibs; 5. removing hydrogen sulfide from various industrial processes; 6. electrolytic cells for various chemical processes (as a component of mixed-metal oxide anodes); 7. optical sensor device; 8. radiotherapy (particularly of eye tumors). mol-1 (first), 1980 kJ.mol-1 (second) The term "gold" was derived from "geolu", an Old English Anglo-Saxon word which means "yellow". Its symbol "Au", on the other hand, originated from "aurum", the Latin word for "gold". The exact period when gold was first discovered could be a subject of dispute. Some of the well-known ETFs include iShares Silver Trust (with ticker symbol NYSE: SLV), Central Fund of Canada (with ticker symbols TSX: CEF.NV.A, NYSE: CEF), and ETFS Silver Trust (with ticker symbol NYSE: SIVR). Trading in ETFs means doing away with the inconveniences associated with the handling of physical silver bars. Bullion is commonly made of either gold or silver. Its value is determined by the worth of the metal rather than by its face value as money. To put it another way, bullion is valued based on the mass and purity of the metal used, instead of its artificial currency value. New sources of ore have been discovered and there also have been improvements in the mining and refining processes. The precious metal is likewise obtained as a by-product of mining nickel. Below are some of the properties of iridium. General: Chemical Symbol: Ir Atomic Number: 77 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 9/ 6/ d Atomic Weight: 192.217 g.mol-1 Electron Configuration: [Xe] 4f14 5d7 6s2 Physical: Density (near room temperature): 22.56 g.