German States – Hesse-Darmstadt – 3 Mark – 1910 – KM-375 – NGC AU Details – Surface Hairlines – Something I had not encountered previously from our friends at NGC. This coin has definitely not been cleaned, but somehow has developed surface hairlines that I have not been able to detect with a 10x loupe. Other than the invisible hairlines, this coin does have significant eye appeal and would be an asset to any collection of world coins.