Small golden pearls in an oyster shell?

[Chessapeaknick]

Hi all,

We were at the beach in Belgium today where we found an oyster shell with two small golden lumps sticking out. Could you help idenitfying them? Are these pearls?

Thanks a lot!

Nick

 

[pattye]

Hi Nick, welcome to Pearl-Guide.
Interesting, could you show a photo from the side so we see the area where they are attached to the shell? Thanks!

 

[Chessapeaknick]

Hi Nick, welcome to Pearl-Guide.
Interesting, could you show a photo from the side so we see the area where they are attached to the shell? Thanks!

Hi Patty,

Thanks for your quick response. Please find some more pictures with a side perspective.

All the best
Nick

 

[Lagoon Island Pearls]

This shell presents with two conjoined pearls. Each would have a term of growth within the vestibular mantle as a loose pearl then were erupted into the extrapallial cavity which eventually became fused to the shell. Upon examination of the inner surfaces, the creature had a considerable history of irregular mantle function across the posterior space radiating toward the level of the periostracum (outer edge of the shell). There also exists considerable hyper-calcitic growth along the entire ventral margin.

Leave it as it is. Any attempt to liberate these from the shell would invariably destroy the item. There's not much value here, but it's an interesting piece nonetheless. Likewise, kudos for good observation, a fair question and a nice find.

Thank you for sharing your experience with us.

 

[SteveM]

This shell presents with two conjoined pearls. Each would have a term of growth within the vestibular mantle as a loose pearl then were erupted into the extrapallial cavity which eventually became fused to the shell. Upon examination of the inner surfaces, the creature had a considerable history of irregular mantle function across the posterior space radiating toward the level of the periostracum (outer edge of the shell). There also exists considerable hyper-calcitic growth along the entire ventral margin.

Leave it as it is. Any attempt to liberate these from the shell would invariably destroy the item. There's not much value here, but it's an interesting piece nonetheless. Likewise, kudos for good observation, a fair question and a nice find.

Thank you for sharing your experience with us.

Is the color significant in any way, contrasting as it does with the inner shell?

 

[Lagoon Island Pearls]

Is the color significant in any way, contrasting as it does with the inner shell?

A very good question. I considered this in the differential diagnosis. The valves of Order Ostreidae as we know them are highly calcitic in structure, thus broadly present as white. However in this specimen, the color and surface of the conjunctions appear highly nacreous. Matching this point with anomalies surrounding the posterior adductor muscle clearly suggest the pearls to be vestibular as opposed to pallial onset. As the adductor grows in circumference, it stands to reason the pearls would be erupted. This is further evidenced by nearly matched colors of the striations of adductor scar which are highly nacreous across the entire class (Bivalvia) of mollusks.

 

[pattye]

This would be interesting to display on a small wooden easel in a grouping of treasured items.