Cleaning Shells

by Richard Salisbury

Everyone that first begins shell collecting runs into the problem of how to clean shells. There seems to be about as many ways to clean shells as there are shell collectors. So I'm adding my two cents.

Most people who begin collecting do not give much thought to preserving the animals in the shells. There is however, an easy and effective way to preserve many shells especially the smaller species.

When out collecting carry a small container with a lid to keep your shells alive. Back at the house you can place them in a wide flat bottomed container to sort them. Most shells small enough to fit through the top of a bottle of rubbing alcohol (70% Isopropyl Alcohol) can be preserved. Note: Shells with shiny nacreous surfaces such as Cowries and Olives should never be placed in any kind of chemical. The alcohol will replace the water in the tissues of the animal. This process takes 3 to 4 days. On the fourth day take the shells out of the alcohol, rinse them and sort through them to get the operculums (which are visible) out. Also remove any other shells which should not be placed in Clorox (eg. Mitra casta and Pterygia fenestrata). Rinse the shells and then put them into Clorox. The time the shells can be left in the Clorox depends on the number of shells and their size. Most shells can be left several days without any permanent damage being done to the shell. A few hours for most species will soften or dissolve the Lime encrustations and periostracum. Remove them from the clorox, brush them and pick the remaining encrustations off. Let the shell dry. You will notice that the shells are dull and lack color and luster. Simply spread a little 3-in-1 oil over the surface of the shell. This will bring the color pigments back to the surface. The oil will be absorbed by the shell and will evaporate in a short time leaving a natural appearance to the shell.

Now to the other shells which were too big to preserve. Probably the safest way to remove animals from shells is the natural way of lettimg them rot out. This method will definitely separate the shell collectors from the shellers. Note: Freezing shells is a convenient way of postponing the cleaning portion of shell collecting. Freezing the shell and then letting it thaw out does help to loosen the animals hold, making it easier to remove.

Prepare a small enclosure of about 2 feet by 2 feet, linking the outside with concrete blocks. Allow air to flow through some of the blocks to where the shells will be kept. Place a thick 2" to 3" layer of beach sand, washed in fresh water, down. An easy way of doing this is to dump the beach sand in the "Shell Cleaning Box" and rinse it with fresh water. If you have small children make your box child proof by adding a thick plywood cover and hasp to the top. Shells should never be left exposed to sunlight while they are rotting out. Remember never to leave poisonous cone shells in a box that small children could get into.

Letting the shells rot out isn't the fastest way to clean them but you can aid the process by hosing out the shells once a week with a high pressure garden hose. Rotting is a natural process which is aided by bacteria and insects such as flies and ants. The only drawback to this systems (as any shell collectors spouse can tell you) is the smell!

Short of using scuba gear there is very little one can do to avoid this when hosing out the "ripe" shells. Note: Never bury any shells especially shiny shells. Do not let them rot out underground as the chemicals in the soil will combine with the rotting animal to attact the shell and destroy its natural shiny gloss. Also finding them before the dog does can often be a workout!

ONE LAST NOTE: IF YOU PRESERVE THE SMALLER SHELLS IN ALCOHOL LET THEM SET OUT IN AN EXPOSED AREA FOR AWHILE TILL ALL THE WATER AND ALCOHOL HAS EVAPORATED FROM TISSUE OF THE ANIMALS.

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Additional Reading

Fair, Ruth H. 1976. Chapter 13 "Cleaning Shells - Inside and Out," Shell Collectors Guide. Tokyo, Japan. Charles E. Tuttle Co.