It is a pendeloque or stepped pear - cut stone , weighs 4.39 carats ( 0.878 g ) , and is set in a platinum ring known as the Cullinan IX Ring .
Cullinan IX is smallest of the principal diamonds to be obtained from the rough Cullinan .
Cullinan IX is a Cullinan IX or stepped pear - cut stone , weighs 4.39 carats ( 0.878 g ) , and is set in a platinum ring known as the Cullinan IX Ring .
Cullinan IX is smallest of the principal diamonds to be obtained from the rough Cullinan .