The other day, an interesting treatment for animal horns showed up on a popular forum. The owner had polished them, and they looked like marble.
To achieve the effect, he started by sanding down all of the surface cracks using an 80 grit belt on a belt sander and an 80 grit drum on a spindle sander. It took a bit of force and patience and he cautioned to take steady strokes to keep the surfaces of the horns “flat” or free from dents. It took about 90 minutes per horn to get them sanded down.
After the electric sander, he used a rigid sponge block and 150 grit sandpaper to sand out the scratches left by the coarser grit paper. That took about 20 minutes per horn. The 150 grit was followed by 220 and 320, respectively. To check progress, he took the horns out into bright sunlight where he could see any missed areas.
Following the sanding, the horns were buffed on a buffing arbor with coarse buffing compound for 20 minutes per horn before calling them done.
Clearly, not everyone is going to like this treatment for their horns, but it is an interesting option for collectors with multiples of the same species who are looking for something different to put in their trophy room.