CRC is the coating they do here on Bend, used mostly on knives, not as tough as DLC (DiamondBLACK.)
DiamondBLACK is much harder than chrome, I think Chris needs to try it if he thinks HC wears better in Kydex. We have several big name range instructors across the USA who use it everyday and swear it is the best wearing finish they've ever used.
All IonBond coatings are PVD (that is the application method.)
PVD Silver (TB-30) is a gray/silver coating, not as tough as DiamondBLACK, but a tad thicker in coating, very durable also.