It is just
putty, like
blue tack. But, people in
California call it quake putty because they use it to prevent
valuable things from falling out of shelves when a small
quake hits. Beloved by museum conservators and collectors of
Precious Moments figurines.
Of course, if the quake is really strong, things may still fall out of shelves. But then, if the quake is really strong, shattered Swarowski swans could easily be the least of your troubles.
An unintentionally funny picture of a woman with unintentionally funny hair demonstrating the amazing power of a specific brand of quake putty can be found here: http://www.gotputty.com/images/women.jpg