Rare Mirror Brockage from Egypt

This is a remarkably clear and dramatic brockage error 5 Piastres from the Sultanate of Egypt. It shows an incused, mirrored image of the obverse in place of the reverse. Though the AH1333 date appears twice, the obverse design is absent, and consequently it is not known whether this error was struck in 1916 or 1917. According to Wikipedia:

Brockage errors are caused when an already minted coin sticks to the coin die and impresses onto another coin that hasn’t been struck yet, pressing a mirror image of the other coin into the blank coin. Brockages are relatively rare among modern coins of industrialised countries where mints exercise a strict production control and somewhat less rare among the modern coins of some developing countries which operate their own mint; in good condition, coins with clear brockage are a collector’s item and can sell for substantial amounts of money.

What makes this particular error so interesting is that when this error was discovered, it got enough attention to be featured on the front page of La Bourse Egyptienne (December 7, 1929 issue). The coin is illustrated, with a caption describing the “great interest” numismatists have given this coin where “the reverse is written in reverse.”

Retrograde Dates and Denominations

As stated in this blog in the past (see here and here), there is a number of Arab coins that have errors as part of the die used to create the coin. This is due to an error in design or engraving. A particularly fascinating form is when part of the legend appears in retrograde.

The coins of Muscat & Oman, which were also briefly discussed in this blog, contain a few varieties of retrograde Hijra dates. Specifically, some of the many varieties of the 1/4 Anna coin dated AH1315, have the date in retrograde, with one variety where the characters are also in reverse order. Both varieties are illustrated below.

Retrograde date with characters in correct order:

Retrograde date with characters in reverse order:

Another example that is worthy of mentioning is the Egypt 5 Piastres of AH 1277, regnal year 4. In this case, the character “4” designating the regnal year is the one that was retrograde (actually, upside down but with a retrograde effect). Both examples of a normal and a retrograde 4 are illustrated below.

Example of normal 4:

Example of retrograde 4: