If you are really keen on bits of debris you could try following the directions of the old UK civil Aircraft Inspection Procedures EL/3-1 para 4.3. This was a list of methods for determining what metal is in the oil filter. Of course being British we had no truck with such complexities as Spectro Analysis. I hear there is similar available from the FAA.
Drain the oil filter and wash the debris into a paper filter.
Ferrous metal can be picked up by a magnet. Hot nitric acid will turn yellow or light brown with carbon steel and dark brown with cast iron. No effect on non austenitic stainless steel.
Bronze will develop a white precipitate when boiled in nitric acid.
Mag alloy will react with saturated copper sulphate solution.
Aluminium will cause a solution of caustic soda to be clear. Aluminium alloy will develop a grey or black precipitate.
White metal will dissolve slowly in nitric acid developing black particles in a pale green solution.
Have fun, white coats are available from all reputable outlets.