Pearls from Atrina vexillum

[gustaf]

Just wonder if there is any attempt of culturing pearls from Atrina vexillum?

[Only Natural Pearls]

I would have thought it unlikely as prices and demand are both low. But if you have any nice examples for sale at a reasonable price please let me know, thanks

[Lagoon Island Pearls]

There was some discussion in this thread:

http://www.pearl-guide.com/forum/sho...llum#post72776

From my understanding of pens, cracking is an issue (among other things).

[CortezPearls]

I agree with Dave on the cracking pearls.

But sometimes fishermen find some truly special pearls from the Pen-Shells. Just last week we were offered 3 pearls from Pinna rugosa: they seem very solid and don't have any cracks...the pearls were fished out years ago and the fisherman just kept them in a jar until recently. Here is a photo of these pearls (the 2nd pearl, from left to right is not from Pinna, but from Pteria sterna) & the lone pearl photo is from the large pearl (1.7 grams) on the far left side.



So, sometimes...

[Caitlin]

Is that pearl purple? It is so pretty and iridescent looking, Is it iridescent?

[CLICLASP]

I have the same question than Caitlin, I have one, and thought that Pen pearls were more porcelain-like texture than iridescent

[Lagoon Island Pearls]

I have the same question than Caitlin, I have one, and thought that Pen pearls were more porcelain-like texture than iridescent

Yes. There is (little) or no aragonite and a higher protein content with just enough calcite to harden. Liken it more to tinted resin than mineralization.

Near to all of the "caramels" in my natural collection appear in the manner as yours (lovely btw!). Although not nacreous, they still present with some iridescence.

[CortezPearls]

These pearl are very nacreous, solid...heavy. Most pen-shells I've handled are "lighter" (protein is less heavy than nacre or calcite). Their color is kind of "bronze" (coppery-brown), possibly being fished out during summer. Many pearls come out in this color in August-September.

[Lagoon Island Pearls]

These pearl are very nacreous, solid...heavy. Most pen-shells I've handled are "lighter" (protein is less heavy than nacre or calcite). Their color is kind of "bronze" (coppery-brown), possibly being fished out during summer. Many pearls come out in this color in August-September.

Indeed highly nacreous. I've erroneously confused them with cultured pens, by jamming four types of pearl into one sentence.

I'm out of my league here (but still wanna play ), so please correct me if I'm wrong again, but cultured pens tend to be top heavy with conchiolin?

[smetzler]

In a prior Nautilus-related search for examples of dual biominerality in mollusk shells I came across this image clearly showing a transition to nacre towards the hinge of this Pinna Nobilis.

[Lagoon Island Pearls]

...clearly showing a transition to nacre towards the hinge of this Pinna Nobilis.

Periostracum and prismatic layering is a long part of the life cycle. Nacreous is short.

Highly nacreous naturals would likely have to be three or more years old.

As nice as the nacre is, culturewise it would seem like an uphill battle from the outset.

[Lagoon Island Pearls]

More like how I perceive it.

[CortezPearls]

The problem with culturing Pen Shells is that the animals themselves are so fragile, specially in their initial year of growth, they don't like the handling and their shells are so brittle...then to achieve a good sized animal (for pearl culturing) you have to wait 3 years...then wait 2 more years for the cultured pearl to attain a good nacre thickness and then...very likely...you'll have a pearl that could crack just because the nacre of these species is of this nature (easily dehydrates).

Look at this nice Pen-Shell juvenile...the shell is translucent. Can you imagine how frail this little thing is?



I would grow them for their incredibly delicious scallop meat (hey! we actually grow Pinna rugosa here!)...but not for their pearls. We tried some years ago, but the results were far from being positive.