Ray Bradbury's seminal work 'Fahrenheit 451' is about a world of censorship where books are illegal and burned by "firemen." The only way to get information in this world is through television. The title comes from the fact that book paper will automatically ignite at that temperature, though it's more of an estimate, as different factors can cause paper to ignite at different temperatures.
In 1953, Ballantine Books released 200 limited edition copies of the work that could survive an encounter with Bradbury's firemen. These books were signed by Bradbury and bound in the fire resistant material Johns-Manville Quinterra, a chrysolite asbestos.
Such copies of the book are bound to be worth a lot of money to collectors. Copies in good condition have been known to be offered for as much as $20,000!
For a long time these remained the only books bound in such a way and are currently only one of two such books. The other is Stephen King's 'Firestarter' which has 23 copies bound in the material.