Electrum
Amber is the subject of some curious legends under this
name, but there is also a metallic electrum, sometimes called
orbas by the French. Electrum is an alloy of gold and silver in
the proportion of four parts gold to one of silver. The pale yellow
color resembles amber.
According to Pliny, a cup of this metal has the property of
discovering poison by exhibiting certain semicircles like rainbows
in the liquor, which it also keeps sparkling and hissing as
if on the fire. A black species of electrum or amber is the gargates
spoken of by Pliny and the jet sometimes used in jewelry
