Natural Black Spinel: Natural black spinel looks elegant and able to give a strong contrast against white. Mining is focused in Thailand where the main office of Hsin Yi Gems Co., Ltd is located. Natural black spinal features a uniform texture and high reflectivity characteristics, and a Mohs hardness of 8° capable of withstanding electroplating and hot wax inlay casting technologies. Hsin Yi Gems adopts high-precision and automatic cutting and grinding machines to mass produce the gemstone, and hence able to offer competitive prices in the market. It has now become the most favorite natural black gemstone to use in jewelry and timepieces.