Pio
Naldi's treatise of 1791 gives the following rule for estimating the
value of small, round pearls, weighing less than one carat or four
grains. As the carat value of four such pearls is given as five lire
and 576 one-grain pearls were counted as one ounce, these two numbers
were used to determine the value of an ounce of small pearls. The
product of 576 multiplied by 5 is 2880, and this number was then
divided by 2000, 1000, 500, or whatever might be the number of pearls
in a given ounce. If there were 2000 pearls, the carat value would be
1.44 lire or $.29; if there were 1000, the carat would be worth 2.88
lire or $.57; if 500, 5.76 lire or $1.15, etc.
The same author2
gives tables expressing the values of pearls not perfectly spherical in
form, which he designates as "perle dolce." These pearls he considers
to be worth half the price of good round pearls ; that is to say, 2-1/2
lire (about $.50) per carat for four weighing together one carat. Where
there are as many as three thousand of these "perle dolce" in an ounce,
the 2-1/2 lire base is multiplied by 576, the number of grains given to
the ounce ; this makes the value of an ounce of one-grain pearls $288.
This amount is then divided by 3000, and the quotient, $.096,
represents the value of one carat of these small
