The first purely Islamic gold coin, struck by the Umayyad Caliph for payment of tribute to the Byzantine Empire, which triggered Emperor Justinian II to strike gold solidus coins bearing the first numismatic depiction of Jesus Christ.  These coins are of high purity gold like a solidus and about the same weight.  Religious and military foes, the two empires were still filled with people who traded with each other across these lines.  They all trusted gold.
 
NGC has graded 9 of this date and 3 in higher grades than this coin.