钻石的神秘、形成及古老……


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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.
当你走进一个美妙的晚会，其中最古老的东西是什么呢？不是你的家人，不是你的祖父母，最古老的东西是某人所佩戴的钻石。 天然的钻石是怎样形成的至今仍不是完全清楚，虽然我们知道钻石是由碳组成，但是科学家仍不能肯定碳是怎样到达钻石形成的这一极端深度的。 钻石形成于地球的深处。适于钻石形成的最适深度大约为地球表面120英尺以下的熔浆中。 钻石结晶所需要的温度和压力是令人吃惊的：温度必须超过2000华氏度，压力至少为每平方英寸690,000磅。为了使这一压力便于理解，我们以150磅的人为例，其只能产生每平方英寸3磅的压力。 我们也许并不知道，钻石并不是形成于火山活动，而是由火山活动将地球深处的钻石运送到我们可以得到的位置。 钻石只有在极高的温度及压力下才能维持其本质。理论上，在大气压及较低的压力下，化学物质的改变倾向于使钻石转变成石墨，与用于做铅笔芯的物质相似。