Looking forward to spending months on each pearl, years up to publication—my samples need to be natural pearls and be seen as such by random reviewers or, within reason, anyone inclined to thinking about natural pearls to the point that they'd be reading my writing. Should there be doubt, academic custom demands that reasonable doubt be stated. Truth be told, back when it all started, I had not given a second thought to this matter of natural pearl identification for my kind of scholarly use, since deciding—fairly off the cuff—to call for the most improbably anything but natural pearls for use as samples. Could pearls such as these be replicated in a controlled way...?
Deciding on the 'how's and 'why's of sourcing natural pearls for research got its fair share of work, and explaining: a section of my paper talks of potential sources of natural pearls suitable for research, another names my sources of samples (KEM 672, p. 80)—glossing over the matter of identification beyond provenance. Even today I would not know how to obtain pearls that look like my samples, yet are not natural—consider this an open call for confounding samples. Of course, a great deal of information is extracted out of these pearls—if for just about every other reason but making a call of natural origin. This is the first time I am giving it a thought in writing.
The fine details of pearl structure that tend to interest me are exaggerated versions of shell growth: some more common than others. The luckiest samples are extraordinarily uncommon ! It is tempting, but nowhere straightforward to take this fit between natural pearl cores and shell further, toward using shell as a benchmark for what is possible as early natural pearl growth. My thoroughly destructive methods do give tremendously more detail to work with than non-destructive procedures useful for gemmology might aspire to, however, there is no strikingly obvious choice of what to look for. Of course, if there is a signature of say, grafting, I wouldn´t be finding it my samples. Other models of inducing pearls - the keshi & tokki of the world - are yet another chapter.
All pearl gemmology aside aside, I remain with the time-honored requirement of replication: research ain't right, unless others have a shot at doing the same. Even if the natural origin of pearls is not critical for a future publication as it was for my first, I still must give a practical account of what my samples are. It is indeed very helpful that many details of mineralization, which I am finding in natural pearl cores, can also be found among fine details of shell growth. Then, there are exceptions to every rule, that may look like this:
This pearl will call for a relatively colourful story explaining its origin—in every sense of the word: species, formation, provenance. A few other samples in kind—with no straightforward shell-like mineralization in them—will be getting even less affirmative statements of origin, even thicker documentation. Still, these are my best samples: demonstrating possibilities that common materials are not leading toward. As far as I can tell, chances of finding more anywhere are not great—if, indeed nobody knows how to make more. If cultured pearls do, occasionally, look like this, I do wish to see them—yet another open call for samples—with fair warning: matching my samples by looks does not quite work; it is likely to find pearls that look like mine, yet aren't.
A broad survey of what comes out of the world's pearling grounds, is a stronger identification method that my considerations—if samples like mine were included in such surveys be it for laughs or for completeness ! Such a repository of samples could also answer my kind of academic question, approx.: "Where else is such mineralization found in either natural or cultured pearls?", rather than the usual points of gemological reports.