Gold is a dense, soft, shiny, malleable, and ductile metal. It is a chemical element with the symbol Au and atomic number 79. It has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements, solid under standard conditions. The metal therefore occurs often in free elemental (native) form, as nuggets or grains in rocks, in veins and in alluvial deposits. Less commonly, it occurs in minerals as gold compounds, usually with tellurium.
A new theory based on a simple but viable geologic model claims that over 80 percent of all commercial gold deposits were formed in a flash. Gold seams are formed when mineral-rich waters flow through networks of cracks in rocks some 5-30 km deep. But the exact mechanism through which the gold is deposited is [...]
No, this isn’t some kind of reinvented alchemy or optical illusion. Scientists at University of Southampton have changed the colour of gold, silver and other metals without coating, by using a nanotechnology patterning technique. Applications may include harder to forge currency or encryption of valuable documents, among other. The team of researchers embossed the surface of [...]
The Israel Antiquities Authority said that archaeologists found a 2,000-year-old gold earring next to the walls of the ancient city, under what was a parking lot. This is not the first amazingly well preserved piece of jewelry found in Israel, but many jewish works of art are often found in other places (such as the [...]