Mother-of-pearl: Classic beauty and remarkable strength July 2,
2007 While the shiny material of pearls and abalone shells has
long been prized for its iridescence and aesthetic value in
jewelry and decorations, scientists admire mother-of-pearl for
other physical properties as well. Pupa Gilbert, a professor of
physics, holds an abalone shell. Gilbert and her colleagues are
studying how the microscale architecture of mother-of-pearl, the
iridescent material that lines abalone shells, makes it 3,000
times more fracture-resistant than its mineral building blocks.
Photo: Jeff Miller Also called nacre ("NAY-ker"), mother-of-
pearl is 3,000 times more fracture-resistant than the mineral it
is made of, aragonite, says Pupa Gilbert, a physicist at the
University of Wisconsin-Madison. "You can go over it with a
truck and not break it - you will crumble the outside [of the
shell] but not the [nacre] inside. And we don't understand how
it forms - that's why it's so fun to study." Understanding the
mechanism by which na