The shell of the giant pink queen conch evolved over millions of years into the perfect haven. Now, researchers have probed the mollusk shell's mysterious inner architecture in such detail that they can say just why it's hard to crack. Their work hints at how people, too, could construct light, tough protective materials.
The conch Strombus gigas can resist fracture a hundred to a thousand times better than the mineral that makes up 99 percent of its shell. Called aragonite, this mineral is a form of calcium carbonate that breaks like chalk. The researchers used microscopy to show that a protein surrounds the aragonite crystals throughout the shell. That protein changes the toughness by permitting fractures to spread without shattering the mineral.