The Jewel Box (Kappa Crucis Cluster or NGC 4755) is an open clusterin the constellation Crux, originally discovered by Nicolas Louis de Lacaille in 1751–1752. This cluster was later named the Jewel Box by John Herschel when he described its telescopic appearance as “…a superb piece of fancy jewellery”. It is easily visible to the naked eye as a hazy star some 1.0° southeast of the first-magnitude star Beta Crucis. This hazy star was given the Bayer star designation “Kappa Crucis”, from which the cluster takes one of its common names. The modern designation Kappa Crucis has been assigned to one of the stars in the base of the A-shaped asterism of the cluster
This cluster is one of the youngest known, with an estimated age of 14 million years. It has a total integrated magnitude of 4.2, is located 1.95 kpc. or 6,440 light years from Earth, and contains just over 100 stars.