The application provides a gemstone testing apparatus for testing a specimen. The gemstone testing apparatus includes a handheld casing, a plurality of light sources, a test probe, a photodetector, a processor unit, and a display unit. The test probe is placed at one end of the handheld casing. A first end of the test probe is placed outside the handheld casing. The plurality of light sources is provided for emitting light rays towards an area that is in the vicinity of the first end. The first end is adapted for receiving light rays from the specimen and for transmitting the light rays to a second end of the test probe. The photodetector is arranged to measure an intensity of the light rays from the second end. The processor unit is provided for determining a material of the specimen in accordance to a measurement of the intensity of the light rays.