Recent content by Lagoon Island Pearls

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...

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...

Agreed. Nothing in this item suggests reversion, decomposition nor concretion from any era other than present. No less a near perfect sphere. >15mm.

Even with my zero fluency in oriental languages, I was bewildered why a knot-less strand of mismatched shaped freshwater pearls with a cheap clasp needed a certificate in the first place.

Of course, giving credence to buyer beware admonishments and the need to get a second opinion. And yes, implying common sense terminology as opposed to scientific descriptions of the object constituency.

It's clever, but not an elaborate fake. The flame pattern (if you can call it that) is superficial as opposed to radiating from the nucleus. X-ray analysis would reveal an absence of nuclear material, instead a striated pattern of bisected growth fronts in the views.

The difference between the auction prices then and now is quite stark. $5.1M down to $1.25M (USD). That's an enormous liability. I have no idea of the circumstances which brought this piece back into the market, but I'd suspect an estate sale or asset seizure because it's doubtful the seller...

Yes, it's an interesting tangent to the discussion. I wonder if it's shelled molluscs or all molluscs? If it's the latter, nudibranchs and some cephalopods would be the exceptions for a great part. I would gather it's the former though. We did identify scaphodpods as cross-lamellar, but I'd...

I would gladly, though I know woefully little of Ms. Strack's eruditions. Much of her work is behind paywalls, in expensive books or with presentations at foreign seminars beyond my austere means.

Aside from the assertion, I found this paper greatly intriguing because it lists several species common to us in the Pacific NW and west coast of Canada. Abalone, mussels, scallops, oysters, Manila clams and geoducks purchased at a fish market in China. It strikes home by directly reflecting...

The link is in the title. It's from the same paper in the OP. My apology, I should have been more specific.

Non-nacreous and porcelainous are subjective terms as to appearance. Nacreous, calcitic and calcareous are objective terms as to structure. It is true in the context of comparing one to another, one is non-nacreous if you ignore the barrier part and solely rely on a (flawed?) structural...

As a side note, this is very interesting and something I've alluded to for a long while. ---------------------------------------------------------------------------------------------------------------------------------------------------------------- Zhu et al. (2016) reported that no...

Ok, revisiting the OP, this: ------------------------------------------------------------------------------------------------------------------------------------------------------------ Similar to Bivalvia, shell structures underlying the myostracum layer in the Polyplacophora, Gastropoda...

Again agreed mainly because of the conflation between the two terms. The burning question being, which came first, the chicken or the egg. We also agree on the majority of cases where once mythical non-nacreous objects are indeed nacreous in terms of structure. Clams pearls for certain. Even...