Natural stone includes everything that can be found in nature, such as granite, marble, travertine, limestone and many others. Some of these stones are harder than others and therefore you may have a much more difficult time making them darker. Choosing to darken a porous stone, such as limestone, is not a very difficult process. It is still possible to darken the harder stones but they need to be unsealed in order for any darkening to occur.
Clean the stone's surface with a natural stone cleanser, such as Mira Soap, and water. Allow stone to dry fully before beginning.
Choose a stone enhancer or stone stain. Examples include Bonstone Stone Enhancer and Marble Infusion Color Enhancer, which can darken natural stone up to a few shades. Put on gloves before beginning application. Test a small area before applying to the entire floor to make sure you like the look of the enhancer or stain. Try to test a spot in the least noticeable area possible in case you are not happy with the results.
Follow the manufacturer's directions when applying the enhancer. Apply stone enhancer to the stone's surface with a sponge or a sprayer to areas that you want to be made darker. Some products will direct you to wipe off any excess while others direct you to leave the surface alone, so read the directions carefully.
Wait the recommended time before applying another coat. Apply as many coats as needed to reach the colour that you desire.
Allow to dry fully before utilising the stone's surface for any purpose. This amount of time may vary, but could be as long as a few days. Refer to the manufacturer's directions for more precise drying times.