Hi PaulG, welcome to P-G
GemGeek summed it up perfectly. Every few weeks we'll see a post when someone finds a pearl in their dinner. Although common, when one considers the sheer volume of oysters and clams going to market, it's actually a rare event.
Very often, new posters will ask about value. At P-G, we're apprehensive to appraise value for many reasons, but mainly because we only have images, not lab reports. Likewise, beauty is in the eye of the beholder and pearls vary broadly, hence value is a unique process between buyer and seller. Nonetheless it's always wise to seek cursory opinions, even if the information is incomplete or in the absence of elaborate testing.
Nearly all pearls are considered "nacreous". In the pearl realm, nacre is comprised of protein, aragonite and calcite. Both aragonite and calcite are calcium carbonate variants. In the ratio they present determines a pearl's value. For example, pearl farmers target species which are "highly nacreous", suggesting high percentages of aragonite to calcite.
Pacific or Atlantic oysters are:
Class: Bivalvia
Order: Ostreoida
Saltwater pearls predominate from :
Class: Bivalvia
Order: Pterioida
Freshwater pearls predominate from mussels :
Class: Bivalvia
Order: Mytiloida
Pearls from edible oysters (and most clams) have a higher ratio of calcite to aragonite by nature. Cooking will remove surface proteins and convert aragonite to calcite.
One other point to consider is the source of the oyster. The greatest portion of edible oysters are from farms. Although their growth is largely up to nature, there is a reasonable probability the formation of a pearl was incidental to some form of human intervention. (ie) hatchery parasites, cracked shells or location relaying.
. Not knowing much about pearls I was just wondering what the approximate value of such pearls would be. Any insight would be greatly appreciated. Thank you.
