Most gems have been treated in some way to hide flaws or to enhance the color or clarity of the stone. Buying a gemstone that has been treated is a great way to get a beautiful stone at a reasonable price. The price of the stone reflects the quality. Common treatments include heat and radiation to change or enhance the color, diffusion to deepen the color on the stone's outer layer, oils and waxes to fill in fine surface cracks and enhance the color, fracture filling to coat the stones with a clear or colored epoxy, resin, or other substance that will fill cracks, and laser drilling to remove inclusions (flaws) and improve the stone's clarity. Most colored stones on today's market have some sort of treatment (some are permanent, some are not) to bring out the beauty of the gemstone.