We would never know about diamonds were it not forvolcanic activity, for that’s what delivers diamondsfrom deep inside the earth to where we can get tothem. Theoretically diamonds can remain diamondsonly at high temperature and pressure. In theory,at atmospheric pressure and lower temperaturechemical changes are liable to take place thatchange diamond into graphite, similar to the stuffpencil leads are made of. However, it has beencalculated that even if this change were to takeplace it would take over ten billion years to happen.Now back to the diamond’s age. Scientists think diamonds may have been formingthroughout earth’s history. Many have been found that are three-point-three billion years old.And the young ones are a mere one billion years old.

我们永远不会知道钻石是否火山活动形成的，因为正是火山活动将砖石从地球内部深处带到我们能找到钻石的地方。理论上钻石只有在高温和高压下才能是钻石。从理论上讲，可在大气压力和温度较低下钻石很可能发生化学变化，变成类似铅笔芯的石墨。但是，据估算即使这种变化发生，这需要十亿年。现在再来说下钻石的年龄。科学家认为，钻石的形成可能贯穿整个地球的历史。许多钻石的年龄是33亿年。新形成的只有10亿年。