The Collapsed Star Fragment is a resource needed for the Artifact Decrypter. Collapsed Star Fragments will occasionally drop from around LvL22-Bosses like Tech-Hunters and Guardians.
With Patch 13 (April 2nd 2015) the "World Artifact Decrypters have been re-enabled" according to Bitmonster. With Patch 15.3 the drop rate of "star materials" was increased by 10%.
Recipe for the Artifact Decrypter:Edit
|Collapsed Star Fragment||1|
The Artifact Decrypter can be upgraded to higher levels with more of the same resources, so also needing more Collapsed Star Fragments (2 for LvL2, 3 for LvL3, another 3 pieces again for LvL4).