時(shí)差N小時(shí):鉆石的年齡(下)

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.

我們永遠(yuǎn)不會知道鉆石是否火山活動形成的，因?yàn)檎腔鹕交顒訉⒋u石從地球內(nèi)部深處帶到我們能找到鉆石的地方。理論上鉆石只有在高溫和高壓下才能是鉆石。從理論上講，可在大氣壓力和溫度較低下鉆石很可能發(fā)生化學(xué)變化，變成類似鉛筆芯的石墨。但是，據(jù)估算即使這種變化發(fā)生，這需要十億年?，F(xiàn)在再來說下鉆石的年齡?？茖W(xué)家認(rèn)為，鉆石的形成可能貫穿整個(gè)地球的歷史。許多鉆石的年齡是33億年。新形成的只有10億年。