'Real' Leather
In this day and age of plastic this and plastic that, the smell of new leather has become a premium sensation, not unlike that 'new car' smell, or the smell of pine tar and marline around an old bosun' locker; a new leather holster or belt is a real treat for both eyes, and the nose as well.
Growing up in the midwest years ago, I can remember when the area 'farm stores' included a saddlery and/or tack shop. It was an enjoyable place to hang out, just because of the aroma.
If you have ever wondered how leather gets from the field to the craftsman's table, the Hermann Oak Leather Company in St. Louis, MO has produced an educational video of the process. They are still doing it the old fashioned way.