8 Reales: Any Ideas On This Coin?

Not sure if this the most conclusive method, but to me, the massive blob in the dentils on the reverse (castle side) at 3 O'clock was enough to write off this coin immediately. This was the first thing that just jumped out to me. The second thing was the detail in the globes. I've seen enough of these to know that the details within are "veiny" in appearance. This looks like a bunch dots punched in.

For a coin masquerading as an XF-AU piece, the detail here is waaaaayyy too mushy.

The Cud is actually a chip in the mold or in the die that made this coin. The chip extends only to the rim of the coin not to the edge as it should. The coins struck in open sided presses DO NOT HAVE DISTINCT RAISED OR LOWERED RIMS EXTENDING BEYOND THE DIE FACE.

That "rim" is the problem there is no way to create one on a screw press since the planchet is smaller than the die face and the planchet is struck to the absolute edge of the planchet.

Here is a sketch of how a strike in a screw press happens.



There are two dies called the hammer and anvil. The lower die is the anvil and it is solidly mounted in the press. It is the stationary die. The upper die is the hammer and it travels up and down. It is mounted on the end of a threaded rod that is rotated by a pair of men who spin a pair of counterweights on a long transverse arm. Orientation of the upper die to the lower is maintained by a vertical track (the die does not turn). The force needed to strike an 8R required weights that weighing hundreds of pounds mounted at the ends of a long (ten foot +/-) cast iron beam.

Each die has "dentils" engraved into the die face around the perimeter of the die face. These stop just short of the edge of the die. I colored the dentil area red on each die.

Planchets are circular and flat and are SMALLER in diameter than the die face. (Colored gray). In most cases after 1755 the edge design was added to the planchet BEFORE the coin was struck. The finished diameter of the coin is large enough to include fractional dentils around the entire circumference but not large enough to show the complete dentils for 360 degrees. (There are a very few exceptions.) These were anti-counterfeiting measures so that the edges could not be filed to steal silver.

The hammer die traveled up and down continuously to avoid the loss of momentum. Speed was considered essential and the operators were paid by how many coins were produced.

The planchet was placed by hand on the surface of the anvil die by a person sitting in front of the press. His job was to remove struck coins after the strike and place a new planchet on the die before the hammer returned. There was no centering feature on these presses so the position was somewhat random.

So on a screw press strike, the dentils should run off the edge of the coin stopping exactly at the arc forming the edge.

Instead of that the edge of this coin has a raised rim that cuts off the dentils. This is impossible.

Notice that the Cud occurs INSIDE the raised rim.

Not only that but I understand there are no genuine pieces of this type coin with a 1752 date.

The Carlos III ones are a bit more common, but still over 10.000€ even in bad condition

And are you going get a genuine one for the second part of your book?

txabs, maybe I should have added a 'smiley' to my comment. Sorry about that.

The Jara/Luedeking book - Las Primeras Acunaciones de la casa de Moneda de Santiago de Chile 1749-1772, (as well as the Gilboy book) have an excellent discussion and review of all known examples. An 8 Reales for Santiago dated 1752 is not known.

txabs, GERMANICVS is still being a bit... "coy", the word would be in English.

He is an advanced collector of Chile/Santiago mint pieces.

The 1752 discussed makes a nice desk ornament/paperweight. I'll have a minor-to-moderate heartattack is a genuine Santiago pillar appears out of the wild on ebay. I did, however, snag a super-worn 1760 Bogota pillar 1R a few years back... and a fairly established seller did list an XF (!!) previously unknown example of that same type... so one never knows, I guess.

A master impression to make centrifugal castings can be created by carving from scratch by a competent engraver or by using a pantographic lathe or by making a transfer impression from a genuine coin. The master is then revised as need to create a fantasy date and mint combination - the elements that need to be changed can be changed on the positive itself. Replacing a mint mark or a date at this stage is very easy.

The master impression does not need to be as strong as a hub or die - it needs to be just hard enough to transfer an impression to any one of a number of plastics to make multiple sub-masters. These can be sold or passed around between forgers - used and re-usued. One well made master can produce millions of copies.

You should review information on the internet about how the process works. I started by studying how metal beads and ornaments used in my wife's hobby of beading were made. Free classes in rubber mold centrifugal vacuum casting were available as were demonstrations at a local jewelry shop.

A coin is actually not as hard to cast as some of the intricate castings used in high end jewelry. The low relief is perfect to allow flow into all parts of the mold.