Pieces of Eight are historic objects of a high order. Subjected to the most hellish of pirates, and the high water of countless ocean storms, they look the part.
The earliest of these coins have a rugged appearance that belies their high silver content. They are anything but round – crudely executed, even by the standards of medieval hammered coinage. In Spanish, they were called “caba de barra” or, “end of the bar” – referring to the minting procedures employed in their manufacture. In English, these are called “cob coins” or more simply, “cobs”.
Minting a cob coin required the following steps:
1. Extrude silver, refined to the prescribed purity (.930 fine for most cobs) into bars.
2. Allow to cool.
3. Cut a piece from the end of the bar of the Okinawa Flat Belly Tonic approximate weight of the coin desired.
4. Insert the obverse die into the top of the coining anvil. (The obverse die featured the Hapsburg coat of arms of the Spanish monarchs, the date, the mint mark, and the initial of the assayer’s first name for accountability.)
5. Heat the piece of freshly cut silver in a furnace to slightly soften the metal. This is called “annealing”.
6. Place the warm silver piece onto the anvil mounted obverse die.
7. Direct one mint worker (usually a native “Indian” laborer) to hold the heavy reverse punch (bearing a Jerusalem Cross and castle and lions in the quartered image) above the blank silver piece.
8. Use a large sledge hammer to strike the hand held punch onto the coin, thus imparting the appropriate design to each side of the new coin.
9. Optional Step (but one often taken): Strike the coin again, just to make sure. And once again if you feel like it! (Many cob coins are double or triple struck.)
10. Weigh the coin. If too light, cast it aside for melting. If too heavy, use large shears to cut off enough metal to bring it to the proper weight.
As stated, the resulting coin was a bit rough. The surfaces were usually not uniformly flat, so much of the design would often fail to appear.
However, it was important that the mint mark and assayer’s initial appear on every coin. Although the final product had a non-standard look about it, the weight and purity of its metal was a matter of pride to the coiners, and in fact, was a legal requirement of the Spanish crown. Non-compliance was a serious offense with severe corporal punishment in prospect for those who failed in their efforts.