Found it while I was changing the oil and filter in my truck. I see that I now have a small oil leak. It wasn't there the last time I changed the oil. But hey, it's got 180K miles on a 15 year old truck. Can't expect them to not spring a leak sooner or later. But anyway, this is what I can't figure out. There's no fluid that resembles this... It's the color and consistancy of anti-seize. No reason it should be mixed in with an oil leak. I inspected both the old filter and oil that I drained and didn't see anything metallic. Keep in mind, I've serviced thousands of vehicles in my life and never came across this before.