Blue orb ~ 3 mm round facetted blue sapphire bezel set in 18kt yellow gold with planished finish, 14kt rose gold orb light accent wire on 2 mm round sterling silver band, matte finish. 

Just for fun:

To the ancient and medieval world, Sapphire of heavenly blue signified the height of celestial hope and faith, and was believed to bring protection, good fortune and spiritualinsight. It was a symbol of power and strength, but also of kindness and wise judgment.

can range in size from small to large. Many people believe that a is an or spirit guide. The orb is considered a spiritual omen or form of communication. This blue orb theory embraces the messaging as one of spiritual guidance. Some people believe that spirit guides take on an orb form since it requires less energy output than a full-bodied apparition. Others are left wondering what a blue orb is.