Recently, I came across an interesting article that originally appeared in the "Saudi Aramco World" journal in 1981. Its title was "A Special Luster", and it describes the usage of gold coins in the Arabian world through history.

I did not know that even as lately as in 1947, the Saudi government did not accept paper money, but it insisted to receive royalties from Western oil companies in gold. Therefore the company Saudi Aramco, partly owned by American investors at that time, had to deliver gold in forms of special discs:

"Similar to coins, they were minted by the Philadelphia Mint in the 1940's for Aramco, and bore, on one side, the U. S. Eagle and the legend 'U. S. Mint, Philadelphia, USA' and, on the other side, three lines on the fineness and weight. They looked like coins, they were used as coins, but, technically, they weren't coins.

In the 1950's, numismatists were puzzled by these "discs" until - in 1957 - the story emerged in The Numismatist. Aramco, required to pay royalties and other payments in gold to the Saudi government, could not obtain the gold at the monetary price fixed by the United States so the U. S. government specifically began to mint the "discs" - actually bullion in coin form for these payments. In 1945, for example, the mint turned out 91,210 large discs worth $20, and, in 1947, 121,364 small discs worth $5, according to The Numismatist."

(Robert Obojski, Saudi Aramco World, 1981.)

Browsing the net, I found the image of a "disc" on an auction site:

Footnote: Wikipedia writes:

In 1973 the Saudi Arabian government acquired a 25% share of Aramco, increased this to 60% by 1974 and finally acquired full control of Aramco by 1980. In November 1988 the company changed its name from Arabian American Oil Company to Saudi Arabian Oil Company (or Saudi Aramco).