They appear to have been cast - only the rounded top is shiny, as if they were cast in tiny moldsMost are round, about 5/16 diameter and about 1/8 thick, all identicalA few are the same metal and thickness, but rectangular, about 3 x 5/16 inchI could try to get a density but the cross-section is not rectangular.
Measure the weight of a bunch of themThen take a beaker filled to a certain levelDrop in the items and note the change in volumeUse enough to get a reasonable change in volume, you don't want to be measuring (if you can) 10.0 mL to 10.8 mL but I don't know how many you haveCalculate the density using the mass and change in volume Al has a densty of 2.7 g/cm3, Mg has a density of 1.74 g/cm3, Ti has a density of 4.5 g/cm3 Should be easy to tell which one you have.
