A certified ruby stone is a gemstone that has been evaluated by a gemological laboratory and granted certification of its authenticity. A ruby is a highly sought-after gemstone, and certification helps to ensure that the stone is genuine and of a certain quality. A certified ruby stone will come with a certificate from the laboratory that evaluated it, which includes information about the stone's characteristics such as its color, shape, clarity and carat weight. The certificate also includes a unique serial number that can be used to track the stone. When buying a ruby stone, it is important to make sure that it comes with a certification from a reputable gemological laboratory. This will ensure that you are getting a genuine and high-quality stone that is worth the price you paid for it.