The diamonds on earth are believed to have formed under high temperature 1000 and pressure 45 kilobar in the deep 100 - 300 km interior of the earth , and brought to the near surface by volcanic activities 地球上的钻石相信是在100至300公里深，温度接近摄氏1000度，而压力达45千巴的地底形成，其后因火山爆发而带至地面。