What kind of Trochidae is it?

[vaparker]

I have some sort of Trochidae shell that is pearlescent and smooth all over.  Is this a particular species or has this shell been modified in some way?  It is very shiny.  It looks like it is entirely of mother of pearl.

Thanks!

[paul monfils]

Many species of Trochidae and Turbinidae have mother of pearl interiors, so commercial shell outlets that supply items for tourist shops, etc. make decorative items from them by grinding or etching off the outer layers of shell until they reach the interior pearly layer, so the exterior looks pearly.  For the most part such shells are of little interest to collectors.  They are decorative only.

<a href="http://www.shellhorizons.com/details.asp?ProductID=S1-37&Page=3" target="_blank"><!-- m --><a class="postlink" href="http://www.shellhorizons.com/details.asp?ProductID=S1-37&Page=3">http://www.shellhorizons.com/details.as ... -37&Page=3</a><!-- m --></a>

<a href="http://www.shellhorizons.com/details.asp?ProductID=I1-6&Page=3" target="_blank"><!-- m --><a class="postlink" href="http://www.shellhorizons.com/details.asp?ProductID=I1-6&Page=3">http://www.shellhorizons.com/details.as ... 1-6&Page=3</a><!-- m --></a>

<a href="http://www.shellhorizons.com/details.asp?ProductID=E3-17&Page=4" target="_blank"><!-- m --><a class="postlink" href="http://www.shellhorizons.com/details.asp?ProductID=E3-17&Page=4">http://www.shellhorizons.com/details.as ... -17&Page=4</a><!-- m --></a>

There is one species of Trochidae in which the outer shell layer is so thin that the inner pearl layer actually shows through, and in some specimens the thin outer layer is actually worn away so the exterior of the shell is naturally pearly. However, this species is also made artificially pearly by manual removal of the outer layer, usually followed by polishing to a high gloss.  The species is argenteonitens, which means "bright silver".  The genus variously appears as Ginebis, Bathybembix, or Lischkeia. I'm not sure which one is technically more correct.  If you go here and type "argenteonitens" in the "species" box, you can see a number of specimens with varying degrees of "pearliness":

<a href="http://www.conchology.be/en/home/home.php" target="_blank"><!-- m --><a class="postlink" href="http://www.conchology.be/en/home/home.php">http://www.conchology.be/en/home/home.php</a><!-- m --></a>

If your shell is more than 50 mm it is most likely a "pearled" Trochus niloticus.  <span class="petit">--Last edited by Paul Monfils on 2009-04-21 19:21:39 --</span>

[vaparker]

Thank you for your help.  I did suspect it had been altered from its natural state.  

I have a collection that was my dad's (he used them for teaching biology). It includes large pieces of several different kinds of coral, a few abalone shells, conchs, whelks, and many that I have no idea what they are.  Do you know of anyone in Virginia or North Carolina who might be willing to help me identify these things and tell me if any are of real value? I can't really devote the time necessary to id them, nor do I know enough to be certain of my identification. I could really use some help.
Thanks again.

[paul monfils]

If you can post a reasonably clear group photo of the shells (or a few images if there are a large number of them), there are folks here who can ID them for you.  You can either post images here, or post them elsewhere and provide a link to them.

This page may help:

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