​Metal, gold and silver, 1 inch long, very light, fell from every vent in new apartment

Metal thing fell from vent, roughly 1 inch, gold and silver, found on floor underneath all vents in new apartment

Moved into a new apartment turned on the heat for the first time, within 30 minutes all vents made a loud noise and a pop. Found roughly 8 of these scattered underneath all vents.

Metal things say 165 F, globe 22, and a J at the bottom