Metallic Flakes

While cleaning my Lugers (all DWMs), I've noticed what appears to be very, very small metallic particles on the dirty patches. These are so small that you can barely see them, and the light has to be just right. It just appears that a 9mm sized patch has 8-10 minute particles that catch the light. Don't notice this all the time, and I haven't noticed whether it was a result of cleaning the bore or the action, but it concerns me. Is this typical?