Knights of Malta Coinage Errors

By John Darmanin 

The topic of numismatic errors is both intriguing and complex. To achieve a fundamental understanding of error coinage, one must be familiar with the processes used to produce coins. The earliest coins of the Knights of Malta (KoM) were probably hammered or struck by a mill press. These early coins are beyond the scope of this article. Only observed types of errors struck during the seventeenth and eighteenth centuries will be discussed.   

Any collector desiring to study the coins produced by the Knights during their reign in Malta (1530-1798) should become familiar with The Coinage of the Knights in Malta by Restelli and Sammut (RS). This excellent book is the most complete work to date and has become the standard reference for the collector. The coinage of each Grand Master is broken down by denomination and variations of design and legend. Each coin has been assigned a number that can be used for identification purposes. These numbers will be used to reference a specific coin throughout this article. 

For the period between the 1600’s and the late 1700’s, no steam engines were known so production used animal, water, or human power. Gold, silver or copper was produced into blank planchets for coin production by several possible methods. The material might have been rolled or hammered into strips of metal of an appropriate thickness. These strips were then punched using a “cookie cutter” type of press to produce the blank planchets. For gold and silver, these blank planchets were then weighed to determine if they met specifications. If the blank was overweight, a file was used to reduce the weight, and bring the coin to within specifications. Sometimes, these file marks were deep enough to withstand the striking process. This resulted in groups of parallel lines showing on the finished coin that resembled scratches. These lines are known as adjustment marks, are part of the minting process, and are not considered damage to the coin. 

The only planchet errors listed in (RS) are Antoine de Paule #41 and #51. Although these coins were probably hammered, they serve to illustrate a type of error. If planchets were in short supply, previously struck coins might have been used as a possible planchet source. Both of these coins were struck using previously minted coins of another Grand Master. This is known as an overstrike.   

Some coins have edge designs or lettering on them. These markings were applied prior to the striking of the coin by a Castaing machine, invented by French engineer Jean Castaing around 1679. The edge design was applied by rolling the blank planchet between opposing dies called cheeks The only error from this process listed in RS is Emmanuel Pinto #74. A struck Spanish coin or blank planchet was probably used as the planchet source. This is probably not normal mint product. It is possible that this was an experiment by the mint. 

The dies used for striking the KoM coins were all engraved using punches and other hand tools. All the lettering and designs on a die appear as the mirror image of the coin design. A number of coins are known with inverted or sideways letters (and numbers). It is possible that the workers used for die production were not literate. This may also account for the different spellings (or misspellings) on the coins. These are considered design errors by some; but are normal production strikes. There are numerous examples of letters or numbers being double punched into the die. The double punching is typically observed at the serifs or loops of the letters in the legend.  These variations can be linked to a particular die and may be used by the specialist to identify die or punch usage. 

The German silversmith Marx Schwab first used the screw press about the year 1550.  It took nearly 100 years for this type of machine to achieve widespread usage throughout Europe. It is unclear exactly when the screw press was first used in Malta. The screw press has a threaded (screw) shaft mounted vertically to the top of the press frame. The upper die (hammer die) was attached to the lower end of this shaft. The lower die (anvil die) was rigidly mounted to the frame of the press. Attached to the other end of the screw shaft is a bar with counterweights on each end. It took three (or more) men to operate a screw press, one (or more) on each end of the weighted bar and another man seated in front of the press. The seated man would insert blank planchets and remove the finished coins. The other men would pull on leather straps attached to the ends of the bar. As the leather straps on one end of the bar were pulled, the movement drove the upper die downward towards the blank planchet and lower die. Then, the leather straps other side of the bar was tugged, the screw raised the upper die and the seated man would remove the finished coin. A good team of coiners could turn out several dozen small coins per minute.

Screw Press used by the Knights of Malta 

A few coins are listed in RS with two obverses or reverses. Each side appears normal with respect to the design and strike. This error is the result of the mint worker using the wrong die when setting up the coinage press. This is a very unusual occurrence, so much so, that it doesn’t have a generalized name. The occurrence of this type of error proves to the numismatic researcher that multiple dies of a given denomination were produced at the same time. The illustration below shows the usage of similar dies for both sides of the same coin. For a complete description of the coin, please refer to John Gatt’s web site.

1703 Grano With Two Obverses 

Several types of coin errors have been observed as the result of production problems. If a struck coin sticks to the die, and another blank is then struck, the resulting coin is known as a brockage. The previously struck coin would act as die causing a mirror image of the design being struck into the blank planchet. The resulting coin would have two obverses or two reverses. One side would have a mirror image of the other with the design being “incused”. The design element is sunken into the surface of the coin instead of being raised.  Several of these are listed in RS. Examples are Ramon Perellos y Roccaful #59, Emmanuel Pinto #227, and Emmanuel de Rohan #101 and #135. 

If a coin from current production is re-struck, it is known as a multiple strike (double, triple, etc.). Because coinage of this period was not produced on high-speed machinery, I would not expect many errors of this type to exist. Multiple strikes are probably the result of struck coins accidentally being mixed with the blank planchets. Multiple strike coins could be the result of equipment set-up and are typically destroyed before being released from the mint.

Another type of production error occurs when the two dies in the coining press come together without a blank planchet between them. This usually results in significant die damage. Part of the design from each die will be transferred to the opposite die. Most frequently, this transfer of design will result in incused letters observed between the lettering of the legend. The technical term for this design transfer is “die clash”. RS lists a number of coins with this kind of die damage such as Emmanuel Pinto #228, and Emmanuel de Rohan #22 and #29 (plated in RS). This Emmanuel de Rohan #29 is a classic example of the die clash.. The cross from the obverse crown shows in the area below the bust next to the eagle on the reverse along with the letters “HOSPITA” near the abbreviation “M.M.”. 

Typically, the legends and inscriptions near the edge of the die are deeply cut into the die surface. These areas may collect dirt, oil, metal flakes, etc. If this foreign material fills a portion of the die, design details may fade or completely disappear. This could explain why a letter, colon, or stop seems to change or disappear. Only detailed comparison with coins having normal inscriptions will determine if this is a blunder by the die sinker or a filled die.

 Many dies remained in use until they became unusable. Metal fatigue often resulted in a crack developing in the die. This crack would be noticeable on struck coins as a raised line that is not part of the design. The crack in the die was likely to grow in width and/or length with continued use. Eventually, the crack could grow until a piece of the die would fall out. This would result in a raised lump of metal appearing on the coin. It is typical for these cracks to develop near the edge of the coin but cracks can be found at other locations. Most of the die cracks observed are on the coinage of Pinto and De Rohan. These die cracks only add to the charm of the coins and are popular with some collectors.

It is up to the collector to decide where the error coin fits into a collection. Some types of errors such as brockages and double struck coins are individual mishaps and may be considered unique by definition. Others, such as spellings errors and inverted digits, usually exist as multiples and may be common for the issue. Continued research by collectors may lead to additional discoveries of errors such as major off-center coins, defective planchets, or the use of wrong planchets for a specific denomination.

 A special thanks goes to The Bank of Malta for providing the drawing of the actual coinage press used by the Knights of Malta. And finally, my deepest gratitude to John Gatt for providing the collecting community with the wealth of information contained in his web site. His continuing hard work has brought together the collectors of the Knights of Malta coinage.