There were Five Dragon orbs on Krynn.
One was obtained by Lorac before the Cataclysm in the Tower of High Sorcery. In unaltered timeline, Fistandantilus taught him to use it, as Raistlin travelled through time, he assumed Fistandantilus's identity and repeated all his deeds, including this one.
In the time of the War Of The Lance (~358 AC), it was the same orb subdued by Raistlin and taken from dying Lorac. Later he kept it and took with him to the past, creating an alternate timeline, when both orbs were present: one with Lorac, and another (aged copy of the same one) - with Raistlin.
The second was captured by Laurana during the battle at the Ice wall (covered in detail in Dragons of the Highlord Skies, only referenced in Dragons Of The Winter Night. Then it was a constant cause of disputes and quarrels, until
destroyed by Tasslehoff.
The third was discovered
by Laurana in the Tower of High Clerist at the end of the book.
The fourth is believed to be destroyed in Cataclysm.
The fifth is only mentioned in context of creation. It's fate and whereabouts are unknown.