Tom Watters' sagacious remarks jogged my memory a little. Here are are few
more factoids regarding pearl culture.
I believe all nuclei are supplied from Japan for world-wide requirements.
They probably have specialized machinery for that purpose, so there
definitely is no incentive to change from the current system.
Prices are important to tourists and here are a few ($US): The farms have
about $300 invested in each "working" oyster. It takes 2 years to grow a
pearl, and oysters can last up to six pearls (12 years). After that,
polished halves are sold to the tourists for $30 each.
There are many criteria for the perfection of a pearl (but I've lost the
industry brochure on that subject).
A fairly perfect large pearl (for earrings) is on the order of $1,000
The oysters are protected--not because of rarity, but I presume for
political reasons: they provide jobs. New oysters are collected with hookah
setups.
The visit to the pearl farm was really very interesting (I should have
taken notes). But the best part of all was that my wife was not
particularly attracted to any...
 
John Wolff
2640 Breezewood Dr.
Lancaster, PA 17601, U.S.A.