Cobs are the original "treasure coins."
Struck and trimmed by hand in the 1500s
through 1700s at Spanish mints throughout
South America, silver and gold cobs are
handsomely crude, nearly all with a cross as
the central feature on one side and either a
coat-of-arms (shield) or a tic-tac-toe-like
"pillars and waves" on the other side.
Silver cobs are known as "reales" and gold
cobs are known as "escudos," with two 8
reales (about 27 grams each) equaling one
escudo. Some cobs were struck with a date,
and most show a mintmark and an initial or
monogram for the assayer, the mint official
who was responsible for weight and fineness.
Size and shape were immaterial, which means
that most cobs are far from round or uniform
in thickness. Cobs were generally accepted
as good currency all around the world, and
were the exact coins referred to as "pieces
of eight" (8 reales) and "doubloons" (any
gold cobs but originally 2 escudos.)
The Anatomy of a Cob
How is a cob made?
These coins are created by forming slabs of
silver and alloy into long rolls of
irregular thickness. These rolls, while
still warm, would be sliced with metal
shears or a chisel to form blanks or
planchets. Depending on the mint, these
blank slices were snipped to form basic
round shapes. Since this process was done by
hand and much guesswork, many coins had flat
edges from the trimming process. The
leftover snips were collected and re-melted
and used again. Due to this rudimentary
process, no two cobs look exactly alike.
What drives value?
Detail – More detail on the coin directly
relates to a higher value.
Rarity – Level of detail is critical in
determining rarity which is driven by many
different coin characteristics. Locations of
mint and assayer marks, full dates, double
assayer marks and die errors are just some
Provenance & Authenticity – Important for
coins that carry historical significance.
Proving a coin’s background and authenticity
is a critical component and will greatly
increase the value.