How to Clean Seashells

This summer I stayed for two weeks on a little island near Puget Sound and spent many-a-days at the beach collecting seashells. I had made the start of a driftwood and twine dreamcatcher while I was there, but waited until I got home to attach the seashells. When I pulled them out of the bag I realized some intensive cleaning was going to have to happen.

If you’ve been collecting shells at the beach this summer too, check out the steps for cleaning them up so you can start crafting away.

Find out How to Clean Seashells after the jump…

There are two kinds of seashells you can clean – alive and dead. In this tutorial I’m going to show you how to clean dead seashells by removing the periostracum layer (tough layer on the outside of seashells) and algae. Start by getting them all together.

Fill a bowl with about 2 cups of water,  2 tbsp of baking soda, and a dash of salt. Mix it all together until it is fully dissolved. Place your seashells inside for about 10 minutes.

Some of the sand, mud, and algae will come off immediately.

Grab a toothbrush or sponge and softly rub as much of the algae as you can away. Rinse in warm water. Starting to look better!

Fill a bowl with 1/3 bleach and  2/3 water. Set your seashells inside and make sure that they are all fully submerged. I left mine in overnight, but you can do as little as thirty minutes if you’d like. Bleach will sanitize your seashells, get rid of the fishy smell, remove the periostracum layer, and make them nice and bright.

Note: If you have seashells with a natural shine, like a cowrie, do not put it in alcohol. Simply soaking it in warm soapy water and rubbing it with a towel will get it clean.

Don’t they look nice? Rinse the seashells off in warm water and soap. If you want to make them glossy, rub on a layer of mineral or baby oil. I chose to keep mine matte. Set them outside in the sunshine to dry off.

Use them to decorate around your home. Make a dreamcatcher or picture frame!



w. taylor

Hello; I want to remove the brown periostracum coating from (dead) blue mussel shells. I have tried bleach in various percentages, and hard brushing of every kind. It does NOT remove coating. Any other ideas?

Also, how to remove the rust coloring on large N.E. sea clams?

thank you.

W. Taylor

The shells shown are Cockles. Bleaching does not remover the dark coating (periostracum) from blue mussels. I am looking for something stronger, but what?


The best method I’ve found is sandpaper. The sandpaper I used came in a dollar store mixed pack, the piece says “P80″ on the back. You carefully scrape the mussel shell back on the sheet of sandpaper forth not pushing on it or it will shatter. This a version of the method shown in ” Primitive Mussel Shell Jewelry”:

Adam Bein

DON’T use sandpaper without wearing an EXPENSIVE HIGH GRADE STORE BOUGHT PROTECTIVE RESPIRATOR mask or the particles will lodgein ur lungs. VERY bad


It may also work to support the mussel shell with some modeling clay and lightly use a Dremel tool to sand the periostraum off. I’ll try that on the next batch.


Muriatic acid mixed with water. Google it or look up iloveshellingDOTcom. If the shells are small or thin, do not use this.
Be sure to practice on a throwaway shell first.


Hi! I just soaked my blue mussel shells in a water vinegar solution for a few days and the brown coating just pealed off. I used a tooth brush to get any of the other pieces off. Hot water also helps it peal away.

Janet T>

I had found a dead moon shell and it was quite stained with algae. I followed your directions and I’m SO pleased! it looks just beautiful! All the green staining is gone, and all the subtle tans and golds on the outside of the shell are still there. It looks great! THANK YOU

Anne D

Any advice on how to get rid of the soft “hinge” that keeps two sides of a clamshell attached? I twisted them apart (after boiling a batch of “joined” shells, and then freezing them). They were still firmly attached (though opened, with the edible clam parts fully removed…) I was able to twist the two sides apart, but am left with a muscle-like soft piece that I can’t get off of the now-separated shells.


Great article, I usually use a soft brush to cleanup seashell dirt, and a pointy knife to take off sticky parts. It works very well.
I really like to pick up seashell from the beach, and craft macrame and seashell necklaces, bracelets and earrings with them. It is very beautiful and gives a nice boho style.


Leave a Reply

Your email address will not be published. Required fields are marked *