The price-value anomaly is obvious to consumers as they hasten to buy Chinese freshwater bargains. Indeed, pearls from freshwater mussels lie at the center of the liveliest activity in pearling today.

Chinese pearls came mainly from freshwater rivers and ponds, whereas Japanese pearls were found near the coast in salt water. Nearly all the pearls in commerce originated from those few sources.

The largest Scottish freshwater pearl found in living memory is being auctioned, nearly six decades after its discovery. The Abernethy Pearl is expected to fetch between £40,000 and £60,000 when ...