Diamonds are sometimes enhanced, using HPHT, radiation, coatings, fracture filling, laser drilling, among other things. Each of these has its purpose in improving the appearance and saleability of a diamond that might not be popular as it was found from the ground, or created in the lab. Any treatment should be disclosed to the buyer, but that is not always the practice for the dishonest dealers. Such dealers are not common, and do not last long in the trade.