Host: The Gemmological Society of Japan
Recently, synthetic diamonds are often found on the market in Japan. Among them, yellow diamond is often produced by the HPHT method (left of Fig.1), and colorless diamond is often produced by the CVD method (right of Fig.1). These diamonds have several inclusions. One inclusion consisted of metallic about Co and Fe2N. The price per 1 carat is tens of thousands of yen. These diamonds are said to be imported mainly via China and India. These synthetic diamonds have been sold as "lab-grown diamonds" in Japan.