As a measurement of purity, 750 fine gold contains pure gold in 750 parts and other base metals in 250 parts. This measurement means that 750 fine gold is 75 percent gold. Although the purity of gold is measured by karats in the United States and the United Kingdom, there are many European countries using the decimal system to indicate the parts per thousandths of pure metal for silver, gold and platinum alloys.Know More
The parts per thousand purity measurement system is referred to as millesimal fineness, or normal European stamping. The older karat system, sometimes spelled "carat," measures purity by fractions of 24. Gold alloys measured as 18 karat, for example, would represent the presence of pure gold in an amount of 75 percent. The equivalent millesimal fineness measurement for 18-karat gold would be 750.
The purest gold ever produced was in 1957 at the Perth Mint in Australia. The millesimal fineness measurement was 999.999, also referred to as six nines fine. In the U.S., the Federal Trade Commission requires that all gold jewelry sold must be at least 10 karat, 41.67 percent pure gold, and properly designated regarding its purity.
Because pure gold is soft and malleable, it is often alloyed with other base metals to improve its hardness. Gold also has the ability to withstand tarnishing and maintains its color and brightness over time. Gold pieces retrieved from ancient Egyptian tombs appear similar today to their original condition 4,000 years ago.Learn more about Precious Metals & Gems
Hard to find in nature and durable enough to remain in perfect condition for centuries, gold is unlike any other metal in the periodic table. It has been used as currency and as a means to display wealth and power for centuries, particularly among royalty historically.Full Answer >
To melt gold, place the gold in a graphite crucible. Heat the gold to approximately 2,000 degrees Fahrenheit. Pour the melted gold into a mold, and allow it to cool completely.Full Answer >
In addition to standard gold purity markings such as 10K, 14K and so on, real gold jewelry is often stamped with a three-digit code. These codes correlate to the purity of the gold within the piece. Gold marked with the numbers 825 has a purity rating of about 19K.Full Answer >
As of 2014, research suggests that colliding neutron stars created gold by fusing various elements during massive explosions. Neutron stars are the extremely dense cores of dead stars that are left after the stars explode as supernovae.Full Answer >