Rust spot

Reddish or rust color spots can appear on gold coins which may be removed by professionals. A brown or reddish spot on gold doesn't mean the item is not real solid gold.

Often a faint amount of trace metal or other material will get on the dies prior to the striking of the coin or bar. When the coin is struck the molecules of the other metal (or impurities) are then fixed into the coin. They may be so thin or dispersed that they are not obvious to the naked eye.

Other times such impurities may come in contact with the coin blank before striking it into a coin. This surface discoloration can occur on gold coins and gold bars.

What to do about it if your gold coin or gold bar has red or rust colored spotting?

In most cases coin experts recommend you do nothing to a coin that shows spotting imperfections. Any type of cleaning is abrasive and may reduce the grade of a coin and hurt the coin's value.

Unc or UN

Abbreviation for uncirculated.

Uncirculated

A new condition coin that does not have any sign of wear. Sometimes also called mint or mint condition.