In the United States, keeping them separate makes life easier for most journalists, especially since they measure not just different substances but use different metrics: A “carat” measures weight ...

For instance, some jewelry might be 18-karat gold, which means it's only 75% pure gold, with 25% alloy content. In that case, the price you'll fetch for that 18-karat jewelry won't be as high as ...

It’s not the same as carat for diamonds. In gold, carat refers to purity. Pure gold is 24 carats, basically 99.9% gold but it's also incredibly soft and not practical for making jewellery that ...

The conventional mixture is usually three-quarters gold and one-quarter copper, with a density of about 15 g/cm 3. That's not true for this new lightweight gold: its density is just 1.7 g/cm 3.