鉆石的神秘、形成及古老……


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選材／校對／翻譯：hqj5715
You walk into a fancy party. What is the oldest thing there? No, not your in-laws, or even your grandparents. It will be a diamond someone is wearing. It's not completely clear how natural diamonds are formed, and although it is known they are made from carbon, scientists are not sure how carbon gets to the extreme depths at which diamonds are made. Diamonds are formed very deep in the earth. The optimum depth for their formation is about 120 miles beneath the surface, in the molten mantle. The temperature and pressure necessary for diamonds to crystalize are mind boggling: the temperature must be over 2,000 degrees Fahrenheit, and the pressure must be at least 690,000 pounds per square inch. To put that pressure in perspective, a 150-pound person exerts only about three pounds per square inch. We would never know about diamonds were it not for volcanic activity, for that’s what delivers diamonds from deep inside the earth to where we can get to them. Theoretically diamonds can remain diamonds only at high temperature and pressure. In theory, at atmospheric pressure and lower temperature chemical changes are liable to take place that change diamond into graphite, similar to the stuff pencil leads are made of.
當你走進一個美妙的晚會，其中最古老的東西是什么呢？不是你的家人，不是你的祖父母，最古老的東西是某人所佩戴的鉆石。 天然的鉆石是怎樣形成的至今仍不是完全清楚，雖然我們知道鉆石是由碳組成，但是科學家仍不能肯定碳是怎樣到達鉆石形成的這一極端深度的。 鉆石形成于地球的深處。適于鉆石形成的最適深度大約為地球表面120英尺以下的熔漿中。 鉆石結晶所需要的溫度和壓力是令人吃驚的：溫度必須超過2000華氏度，壓力至少為每平方英寸690,000磅。為了使這一壓力便于理解，我們以150磅的人為例，其只能產(chǎn)生每平方英寸3磅的壓力。 我們也許并不知道，鉆石并不是形成于火山活動，而是由火山活動將地球深處的鉆石運送到我們可以得到的位置。 鉆石只有在極高的溫度及壓力下才能維持其本質(zhì)。理論上，在大氣壓及較低的壓力下，化學物質(zhì)的改變傾向于使鉆石轉變成石墨，與用于做鉛筆芯的物質(zhì)相似。