A working draft of Albert Einstein's manuscript on the theory of general relativity was sold at auction in Paris on Tuesday for a record 11.6 million euros (about $13.1 million).

The 54-page manuscript belonging to the German physicist and his friend, Swiss engineer Michele Besso, is "exceptional" given that normally Einstein destroyed the documents and notes he created while working on his theories, the books and manuscripts expert for Christie's auction house, Adrien Legendre, told EFE.

The document, initially valued at between 2-3 million euros, is the "only surviving work detailing the genesis of general relativity," aside from another manuscript at the Albert Einstein Archives at the Hebrew University in Jerusalem.