Tag Archives: black seashells

lettered olive with other seashells

Why So Many Black Seashells?

Seashells come in many lovely colors, but it’s odd to find all black seashells. Certain shells have dark lines or spots and are made that way by the snail inside, but this is different. One day while collecting shells, I found an unusual number of all-black shells.

Sometimes out in the wild a living shell, or shell still under the water, will be covered in a dark, sometimes fuzzy, coating. That is the periostracum, or skin, which creates an outer layer over the shell. I have a horse conch which I cleaned, but never removed all that layer. The shell underneath was still light colored.

But some shells, like these Jingle shells, are all black.   They may have begun as some pretty orange or white color, but have turned black due to the sediment where they were buried. It has to do with sulfur content in the sand, or something. I am no scientist, so I won’t try to explain the process – I would just confuse myself and you! My message here is that they don’t begin black.
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These jingle shells were collected near Ponce Inlet on the East coast of Florida.  You can see that one of them (in the photo above) is just beginning to turn from it’s light orange color.  It may not have been buried as long as the others.  Constant wave action is bound to unearth shells and eventually wash them ashore.

Below, I have worn oyster shells and piece of something that was probably a whelk among the ridged jingle shells.
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The partial whelk shell below has also turned black.  These shells do not start out this way.  Whelks are generally tan with brown stripes or light in color.  The one in my photo below is probably either a Lightning Whelk or Knobbed Whelk.  It’s too broken for me to tell.

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Shells are often not pretty when found. Especially if they are found in the water. They can be dark or coated with green, with barnacles or oysters attached. Shells found up on the sand can be white, or much lighter in color that they were when inhabited. The sun can bleach them. This makes seashell identification harder. It can be just as difficult when collecting shells that have turned totally black.

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black and silver jingle shells

The Mermaid’s Toenails Turned Black

Screen Shot 2017-04-14 at 9.56.28 AMThe common jingle shell (Anomia ephippium) is easy to identify, but maybe not from a distance.  While walking along the shoreline, spotting a black shell could mean you’ve found just about anything.  Any shell can end up turning dark gray or black in color if the conditions are right.

On my latest visit to the beach, I gathered some jingle shells, of which most were black, as you can see in my photo. One is somewhat silver, and another has bits of lighter tan, which means it still retains some of it’s original color.

But jingle shells don’t start out as black.  Just like the lightning whelk below, shells turn black because of sea and sand conditions.  According to a comment left on another blog, The Ocracoke Island Journal, shells that have been washed into a low oxygen area will turn black due to the presence of iron sulfide.  Click the link to see photos of an impressive collection of shells that were washed up on the beach after Hurricane Irene, many of which are black in color.  Scroll down the page to read the comment about black seashells.

Jingle shells can be orange, yellow, white or off white, and gray.   Because of the coloring and their flat shiny surface they are sometimes called “Mermaid’s toenails”.   Once you hold a jingle shell, the difference between it and other shells is readily apparent.  It’s a bivalve, but there is nothing to suggest it was attached to anther piece.  The shell is irregular and somewhat flattened.  They are rarely over 2 inches across in size.

In fact I did collect quite a few black shells that day. I’m not really sure what that black one is in the photo below. It was too thick to be a jingle shell, but had the right shape.

cross-barred venus clam
One of the black shells I found

This piece of a whelk and the pointed bit of shell caught my eye also because of the unusual dark color.  I have decided it is a Lightning Whelk.  It is my best guess as the other side looks like the opening would be on the left.

I don’t think it’s rare to find a black seashell, but the shell was washed up from a place that had the right conditions to turn it into this, from it’s natural beautiful state.

black seashell
Black Lightning Whelk
Lightning Whelk
Lightning Whelk