How to Clean and Polish Seashells

– This one is pretty simple. Find an area in your yard where you don’t mind digging a hole and bury the shells about 18″ down. The reason for the depth is so animals will not find them and dig them up. Also you or your neighbors won’t smell them. Let them remain buried until the insects, ants, larvae, worms and bacteria remove all the tissue and they will darn near polish the inside of the shell. But, this could take as long as a couple of months. The longer you leave the shell buried, the better the job our little friends will do.

Another way you can do the same thing a bit faster is to put the shell right next to a good size ant bed. Now this one does have some unpleasant side affects. It is going to have a bad smell for awhile, even if all you have are a few small shells. You will be surprised at how bad those little critters can smell, and your neighbors might just get mad. Animals can get to them and damage fragile shells and also get sick from eating shells and rotten critters. However if you cover them with something to keep the animals out and let the ants in that will solve that problem. But the interior of the shell will be picked clean in a few days to at most a couple of weeks. Oh, and the ant colony will thrive and grow.

For either method you will still have to wash out the inside of the shell, first with a vinegar and water solution and then with a warm soapy water solution then rinse with fresh water and let dry well.

– Freezing – If burying does not work for you then this method well do the trick and is another pretty fast way to go. Place the shells in a water-tight bag then place the bag in a plastic bowl or container of some kind and cover the bag with water. Place it in the freezer and let it freeze solid. I would suggest at least twenty-four hours. I usually let mine stay for forty-eight. When you are ready to clean the shells, allow them to thaw to room temperature. After they are completely defrosted (Don’t get in a hurry!) You should be able to grab hold of the critter and gently slid it right out of the shell. You will still have to do the Vinegar and water soak and the warm soapy water wash then fresh water rinse but you will have a nice clean shell.

Go to step # 5


Boiling – Take a pot of water large enough to hold the seashells you are cleaning. Fill it high enough so that there are at least two inches of water over the shells. Bring the water to a rolling boil and let it boil for a few minutes. The more and larger the shells, the longer you let it boil. A shell the size of the average fist should boil for about five minutes. Two that size maybe eight minutes. Judging when it is done comes with time and experience. Don’t get carried away and figure I have ten shells so that must be an hours boiling time! It’s not, maybe twenty or twenty-five minutes is the longest I have ever boiled a big batch of shells and that was about thirty big shells in a large spaghetti pot.

Using Tongs and being very careful not to burn yourself, remove a shell from the pot and grasping it with gloves or a towel, gently pull the critter out of the shell. It should slide right out. Be careful, because if the critter comes apart you will have to go back to step one, burying the shell or tossing it on an ant hill, as you probably won’t be able to get the rest of the critter out of there otherwise.

Again, the Vinegar and water, followed by soapy water and then a fresh water rinse will be necessary.

Microwave – This is an easy method if you don’t mind the smell in your microwave. My wife would hand me my head for cleaning if I used her microwave and besides that, I wouldn’t want to use the microwave for cooking if it smelled that way afterward anyway. It can really make it smell bad. But, if you are going to be cleaning a lot of shells you could pick up a cheap microwave or get one at a used appliance store and use it in your workshop or garage or out on the patio or driveway or where ever you clean your shells. The time you need to cook your shells can really vary from microwave to microwave because of the power they put out so really you just try it until you figure out how long to put them in for and then treat them like you would in step 3. But again, remember to be very careful when you pull that critter out of the shell.

As usual, the Vinegar, soapy water and fresh water rinse is a necessity.

Bleaching – DO NOT use Bleach on Naturally Polished Shells like Cowrie Shells, Conus Shells, and Margellidae Shells and such as bleach will damage the already beautiful finish on these shells. In the next section I will tell you how to clean them in Alcohol Cleaning. – After no tissue remains, soak the seashells in a strong solution of pure bleach. There is no set time to let them soak because it varies by the type and quantity of shells you have to clean. It doesn’t matter if you mix all types of shells together. Just be sure to remove the shells after the periostracum is gone. The periostracum is the flaky leathery like covering that covers most live shells. On some types of shells it is thick and takes a long time for the bleach to eat it away, other shells have a thin coating and it goes quickly. You need to keep a watch on it till you know which shells are going to react how in your solution. Be sure to use eye protection when using bleach, also rubber gloves and a rubber apron would be a very good idea. Bleach is a dangerous chemical and can do sever damage, even cause death to humans and animals and severly damage property. Please be careful!

Rinse thoroughly with fresh water and if necessary, brush away any remaining periostracum with a toothbrush or soft wire brush. Rubbing the shells with baby oil can give them a deep luster.


Shells can, after letting them dry for several days, be sprayed with things life clear gloss or satin finish polyurethane. I recommend the satin finish as it gives the shell a more natural finish. This will keep the shell cleaner and it will hold less dust and will absorb less skin oil if handled a lot.

Some people use a fine dusting of a satin finish metallic spray to dress up a plain shell but the Serious Collector would never do any of this. They want a pristine shell. The Decorator and the Artist on the other hand wants to enhance the natural beauty already present in the shell and uses their imagination to come up with things to spark the imagination.

Alcohol Cleaning – Be very careful with natural polished shells like Cowrie and Conus shells. Only use Alcohol to clean them and never use bleach as it will damage the exterior surface of the shell.Soak the Naturally Polished shells in 90% Pure Alcohol, Ethanol, to get rid of the detritus on the surface both inside and outside. If you can’t get rid of the smell with alcohol you can pour a small amount of bleach into the shell through the opening. But be careful not to get any on the polished exterior of the shell as it will damage the surface. Avoid putting a shell that has a little bit of the animal left inside of it into water for more than a minute or two. The rotting bit of animal will secrete an acid that will damage the shell. The first visible damage, and it is non-reversible, is a rainbow-like effect that will show up on the end of the shell. Your nose can detect the bit of critter before any damage is done. Just sniff the shell a few days after cleaning. If you can smell the decay then there is still critter inside and you have to get it out. Your best method is either with a water pick and blast the little bits out or let the ants and bugs do it for you. It’s their job and they do it well. After the critter is all gone rinse with alcohol again an and your shell is done.

If there is a calcium or coral build up a soaking in alcohol and gentle scraping with a dental pick or a wooden pick will take it off. You can rub it with mineral oil or baby oil but never spray one of these shells with any kind of paint or lacquer. Cowries, Conus shells and all the rest of the naturally polished shells are just too pretty to do that to!

Notes Of Interest

1 – If tissue should break off inside the seashell you are cleaning there are a couple of ways to proceed. Shake the shell vigorously and hope the remaining tissue will work its way out. Sometimes this actually works. Another way is trying to squirt water under pressure into the shell and wash the tissue out. Usually not very successful, but known to work sometimes. The last way is to leave it outside for the ants and other bugs to feast on and they will do the job for you then you can just go on to step # 5.

2 – Operculums – This is the trap door of the shell. The hard plate the critter pulls in behind him when he withdraws into the shell and hides from you and other predators. Many collectors like to keep this part of the shell to show that the shell was taken as a live seashell.

3 – Water Picks – Sometimes on the smaller shells another method to squirt them with a water pick and the high pressure will push the tissue out. This will only work with the smaller shells. The critters that live in seashells are tough and water picks just aren’t strong enough for any but the little ones. Water picks can also useful in general cleanup after the critter has been removed from the shell.

4 – Dental Picks – Dental Picks, Electronics Repair tools, Hobbyists Tools and other instruments are often used to help in removing barnacles and other growth on seashells. The odd curves and shapes allow you to reach into the places needed to get the little growths off without damaging or harming the surface of your shell. These can be purchased from many sources like Hobby Shops, Dental Supply Houses, and even places like Radio Shack.

5 – Very Fine Wet and Dry Sand Paper – Very fine wet and dry sandpaper, around 600 to 1200 grit or even finer, can be used to remove built up calcium without damaging the shell finish. If you start loosing the finish on the shell go to the 1200 or finer paper, using it wet, and gently polish it back to a nice luster.

How to clean Dead Seashells
A seashell that is found dead with no animal tissue inside is a lot easier to clean than a live shell.

Calcium and Coral – A good hand held wire brush or wheel wire brush on a Dremal Tool or a small electric drill will take off most of the calcium or coral deposits on a shell. Be careful not to dig into the surface of the shell with the wire tool. Often, you might even want to leave some of the deposit on a dark shell and just smooth it down to leave a random pattern (as shown on the shell above) but that is up to personal taste. After removing as much of the calcium or coral as you want, use very fine wet 600-1200 grit sandpaper smooth and polish the shell to a nice luster.

Barnacles – If after bleaching there are still some barnacles and other matter on the seashells you can use an instrument such as a dental pick to pick them off the shell. Other useful tools are a water pick, tooth brush, a grill brush and Dremel tools.

Rough Lips – If the lips of your shell are chipped or rough and unsightly and the natural state is not important to you, one may use a rotary grinder or file to smooth down the lip. Another great tool for this is the Dremal tool.

Shining – If you want to give your seashells a luster you can wipe them down with mineral oil or baby oil. You can also spray them with something like a clear gloss or satin finish polyurethane. I recommend the satin finish as it give the shell a more natural look with a lite shine.


How to preserve a Starfish – The best way to preserve a starfish is to soak it in a 70% Isopropyl Alcohol solution overnight, if it is a big starfish like the Bermuda Star in the picture you may want to leave it in an extra day. After doing this let it dry out really well on paper towels, out in the sun if at all possible. You will also want to weigh down the legs so that it doesn’t start to curl up as it dries. Do not use something so heavy that it makes a dent in the legs as you will detract from the beauty of your Starfish that way.

How to preserve and harden a Sanddollar or a Sea Biscuit – One of the ideas behind cleaning a live Sanddollar or a Sea Biscuit is also about the least known. To get a Sandollar to bleach white takes patience. It is important to soak it in fresh water first. Here are the steps you should follow to preserve a live Sanddollar or Sea Busciut;

1 – Gather the Sandollars and as soon as possible after you get them, soak them in fresh water. The fresh water will turn brown and after awhile they will begin to smell so change the water frequently. If you are pressed for time try continually flushing them with water. That takes a lot of water. It’s better just to let them soak and change the water regularly. Keep doing this until the water stays fairly clean.

2 – Next, soak the Sanddollars in a 50-50 solution of bleach and water. Let them sit for around ten minutes.

3 – Remove from the bleach and rinse thoroughly in fresh water then let dry.

4 – Repeat steps 2 and 3 as necessary.

Do not soak them for too long in the bleach solution as they will start to crumble if left too long! Each soaking in the bleach will weaken the Sanddollars a little more so it is not recommended you do this more than a couple of times. Sanddollars are very fragile.

If this does not whiten your Sanddollars enough it is best to let the sun bleach them out the rest of the way. If you must, spray them with white paint, but this will look obvious and it is best to let the sun do the job if you can.

To harden the Sanddollars, and Seabiscuits, simply mix together white glue and water in equal portions. Use a sponge brush and completely cover the Sanddollar or Sea Biscuit with the mixture. Let them dry thoroughly. After hardening they may be used in a variety of craft projects or simply displayed on a display stand in their natural state. You can find nice Display Stands on the Internet.

Preserving Sea Urchins
It is a smart move to always wear gloves when touching a Sea Urchin until the Spines have been Removed!

These are extremely delicate so you must be very careful when cleaning them or you will end up with a handful of broken shards. If you have time and are prepared to put up with the smell you can let them sit out in the sun for a few days and then brush off the spines. After this you flip them over and with a dental pick or long tweezers or something similar and pick out the tissue that will be in the middle of the shell. If the odor is a problem you can dip them in bleach and rub off the spines. After the spines are gone take a dental pick or long tweezers to the hole in the bottom of the shell and carefully pick out the tissue. Remember this is a very delicate shell. Dip in the bleach again and rinse well in fresh water and let dry. They are well worth the extra care it takes to clean them. The big ones make beautiful lamps.



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