Pieces of gold with silver inside of a vein of galena crystal, which is inside of a vein of Quartz crystal. The gold is usually in cubes and can vary from huge to microscopic.
Usually they are either Gold or Silver, but but I have seen them in other colors. Usually the colored ones don't play as well and they are just made to look good.
It is a thin layer of a metal which is silver in color that to make something look better. For instance many Trumpets have a silver or gold plating on them so they don't look ugly like the brass actually would. The silver on trumpets is actually usually nickel (and the gold is usually lacquer).
There are a few idioms that have to do with gold. One is: all that glitters in not gold. This means that things that look good are not always valuable. Another is: worth its weight in gold, which means very valuable. Also, one usually used to describe children is: as good as gold. To have a heart of gold is to be generous.
Gold stones look like regular stones with spotspots of gold
916 = 91.6% gold, 8.4% usually silver 999 = 99.9% gold, 0.1% usually silver
Look for anything that is "Hypoallergenic". Gold is usually a good bet, but make sure it is real gold and not gold "clad" or "coated". Clad or coating will wear off and then you're in trouble.
Copper and gold look similar, but while gold is yellowish, copper is reddish.
Not usually since gold is, well, solid gold.
The wedding ring should be symbolic of the marriage. White gold is more common than yellow gold currently. Usually real diamonds are placed in the center of the band.
Gold Olympic medals are real gold, but they are not all gold. They are usually just coated with gold. The rest of the medal is usually silver. There are standards as to how much gold is actually on the gold medals.
The mines where you get gold are usually called "gold mines".