In the real world, blue gold is an alloy of gold and indium. It is not actually blue in color but rather a silvery white, more closely resembles platinum.
In DragonRealms, blue gold is an alloy of gold and indium that is very difficult to produce. The metal is typically described as a cobalt blue with gold marbling. Blue gold is commonly used to form the Shariza symbol of Tenemlor, and is considered very special by the Prydaens. A Shariza isn't considered a true one without it being made of blue gold.
Long-term exposure to necromantic corruption can cause blue gold to become blighted gold.
Blue gold must be provided for alterations.