For 40 years, scientists have theorized that an organic mixture excreted from mantle tissue, which forms oyster skin, induced shell growth.
"New technologies are giving scientists the tools they need to answer the tough questions," said Andrew Mount, adjunct assistant professor of biological sciences at Clemson University and lead author of the article.
When the Clemson researchers used a scanning electron microscope -- a microscope that detects electrons instead of light -- to study immune blood cells from oysters, they discovered that some cells contain crystals.
Based on their observations, the research team concluded that the intracellular crystals are used to form shell. They observed rhombohedral-shaped crystals, leading the researchers to theorize that they were calcium carbonate -- a basic substance in hard tissue. They also observed the number of crystal-bearing cells increased 300 percent when an oyster is healing a shell fracture. Furthermore, the cells travel to the site of shell formation to deposit the crystals.
Scientists and engineers hope that an understanding of biomineralization, the process by which living creatures turn elements into crystals, will lead to breakthroughs in medical and material sciences.
"Nature exhibits exquisite control over the size, shape and organization of crystals," Mount said, adding if engineers can mimic nature, they could build bone replacements, grow crystal communication equipment and design paper-thin protective suits.