The hard metallic inclusions often found in Egyptian gold objects are shown to be mainly composed of osmiridium (natural alloy of osmium and iridium) with occasional small amounts of platinum, rhodium and ruthenium. They tend to be exposed at the surface because of removal of the softer gold alloy by abrasion and may be more concentrated in the part of the object which would have been lowest when cast due to their greater density. One map shows the distribution of known gold-bearing regions in Sudan and Ethiopia, and seven photographs illustrate objects with osmiridium inclusions. -- AATA