Geppetto Necklace
 
The number 1729 on the necklace is known as the Ramanujan number. Famous mathematician Hardy, who came to the hospital to visit his friend and student Ramanujan, tells Ramanujan that the license plate of the taxi he took on the way to the hospital was 1729. Ramanujan thinks about this for a while and says that the number 1729 is the smallest natural number whose sum of two cubes can be written in two different ways. 
 
This necklace is the necklace used by the character named Gepetto in Altar Kaplan's novel "Camus Dance".
 
Dedicated Novel: Camus Dance - Altar Kaplan