Pearls from Britain?

Never knew this, I always thought pearls were from the ocean.

"The river Conway, in North Wales, was of considerable importance, even before the Roman invasion, for the pearl mussel (the Mya Margaritifera of Linnaeus) and Suetonious acknowledged that one of his inducements for undertaking the subjugation of Wales was the pearl fishery carried forward in that river.

According to Pliny, the mussels, called by the natives Kregindilin, were sought for with avidity by the Romans, and the pearls found within them were highly valued; in proof of which it is asserted that Julius Caesar dedicated a breastplate set with British pearls to Venus Genetrix, and placed it in her temple at Rome.

A fine specimen from the Conway is said to have been presented to Catherine, consort of Charles II, by Sir Richard Wynne, of Gwydir; and it is further said that it has since contributed to adorn the regal crown of England.

Lady Newborough possessed a good collection of the Conway pearls, which she purchased of those who were fortunate enough to find them, as there is no regular fishery at present.

The late Sir Robert Vaughan had obtained a sufficient number to appear at Court with a button and loop to his hat, formed of these beautiful productions, about the year 1780."