Today I received the F90T17CW GE bulb I ordered and it arrived safely, but there was a rattle in the bulb and small interior scratches to the coating where something was rattling around.

I checked the continuity of the filaments and they looked ok so I connected it up to the ballast and it worked just fine.
But after hanging the fixture and operating it I noticed that there were two little square things laying at the bottom of the tube at one end.

Are these the electrodes?
The bulb works fine, will this cause the bulb to have a shortened life?
The bulb looks good and has no exterior damage.
How could these fall off?
Should I be concerned or just forget about it since I can't fix it anyway?




  

On some lamps are used cathode guard frames intended to protect the cathodes from ion bombardment (or in some designs act as the primary anodes, so the filament isn't loaded by anode current). These are then usually spot welded and it could be those welds, what gave up. Some designs use metal frames to prevent the electrode sputtering from reaching the tube wall, so cause blackening.
In any case I would expect the performance of that lamp (life, and/or lumen maintenance) will become eventually worse. But you indeed can not do anything about that anymore...