Non-invasive Grading Technique For Ruby Gemstone Using Charge-coupled Device (CCD)

Ruby is one of the most popular and high-value gemstones that always attract the gemologist and jeweler in the diamond market. The wide use of ruby in various industries makes the grading of this gems more complicated due to a lot of synthetic and imitation rubies are made. The current grading techniques are mostly depending on the human visual assessment which prone to errors. This paper proposes a system that helps in grading the clarity characteristic of the ruby in non-invasive manner. The system includes a charge-coupled devices (CCD) and laser that is designed in the most suitable and effective way to conduct inspection on the light intensity of the ruby which will then determine the clarity of the ruby. CCD linear sensor is widely known as the reliable sensor especially when use in the optical system. The CCD linear sensor capture the light intensity from the ruby and convert it into the voltage value. The result shows a value of 1.7918 V obtained from the CCD linear sensor when ruby is placed in the system. This concludes that the CCD system can detect even slightest changes in the light intensity that can pass through the ruby and falls on the CCD linear sensor. The system is proven to be a reliable and effective system with 80% accuracy.