I have to hand it to the diamond industry. Brown colored diamonds, with the exception of particularly large stones, were almost exclusively used for industrial purposes. AS the most common color of diamonds, they were also comparativly inexpensive, again making them attractive for industrial applications.
However, slap the term "chocolate diamonds" on them, and they suddenly become valuable gemstones. Interesting how that stone in the expensive piece of jewelry was destined to become high-grade sandpaper just a few years ago.