Pure gold does not tarnish. Gold items less than 24 carat can show signs of tarnishing because the other metals in the alloy may react with oxygen or other compounds.Continue Reading
Gold jewelry and other items under 14 carat need periodic cleaning. Copper and silver are used in lower carat items. Perspiration, cleaning agents and perfumes can cause these to tarnish. Copper, when reacting with oxygen or other corrosive compounds, produces a green residue. Silver causes black discoloration. Black smudges may be left on the skin when wearing jewelry that is beginning to tarnish.
Polish jewelry often with a soft cloth to remove early tarnish buildup, perspiration or other compounds. Be sure the box, bag or other storage container used for gold is free of sulphur compounds. Some adhesives and fabric treatments, for example, create sulphur dioxide and other sulphuric gases, increasing the rate at which the lesser metals in gold alloy tarnish. Avoid handling gold items after using cleaning chemicals, washing dishes or preparing food. Gold items of lower carat can be plated with 24 carat gold, which prevents any tarnishing in the short term. With frequent wear, the underlying gold alloy is exposed over time and may begin to tarnish.Learn more about Precious Metals & Gems
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.Full Answer >
Gold is expensive because there are limited quantities available. In addition, it is expensive to produce, which also drives up the overall cost.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 >
To clean white gold, soak it in a solution of mild dish soap and warm water, and scrub off dirt with a paste of baking soda. Rinse the gold with clean water, and buff it with a microfiber towel.Full Answer >