Electrum is a naturally occurring gold and silver alloy, but it is also known to have been produced artificially. An alloy is a homogeneous combination (sold solution) of two or more metals. 

Ancient Greeks called electrum simply “gold” or “white gold”. The percentage of gold in this alloy ranges from 45-55%. Ancient Lydian coinage of electrum, usually found in modern Anatolia, contains 70-90% gold. 

It was sometimes used by the Egyptians for the top of their pyramids. They called the top piece a pyramidion and it was often made of this alloy, as it was seen as an important piece. Electrum is also known to be used for drinking vessels and other coins. 

The color of electrum ranges from pale yellow to yellowish-white. While white gold usually contains gold and silver, electrum, in its modern sense is now named for combinations of gold combined with nickel, platinum, and palladium to produce a silvery-gold color.