| Added by |
 Alain Martineau
|
| General Description : | Mollusk shells consist of a calciferous substance that is secreted by the soft mantle tissue and then hardens. Shells have three layers: an inner, shiny layer of nacre, or mother-of-pearl, which is a mixture of calcium carbonate and the protein conchiolin; a central, prismatic layer of calcium carbonate crystals; and an outer, organic layer, the periostracium, made of conchiolin. Many mollusk shells are important commercially because of their beauty and rarity. Shells of the more common mollusks long have been used for the production of synthetic pearls, pearl buttons, and other decorative items. |
| Face value | 22 US cents |
| Catalog code (Michel) | US 1742Dl |
| Series | Seashells |
| Stamp colour | multicolor |
| Stamp use | Definitive stamp |
| Issue date | 04/04/1985 |
| Print technique | Engraved |
| Perforation | 10 |
| Height | 25.00 mm |
| Width | 22.00 mm |
| Catalog prices | No catalog prices set yet |
