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 crystallize 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 3 pounds per square inch.

你走进一个高档的聚会。那里什么东西是最古老的？不，不是你的in-law，或是你的祖父母。而是有人戴得钻石。人们尚未完全清楚天然钻石是如何形成的，虽然知道它是由碳构成的，科学家们还不确定碳是如何到达钻石形成的极端深度。钻石是在地球很深的位置形成的。其形成的最佳深度是在地表之下约120英里，在熔化的地幔曾。钻石结晶所需的温度和压力是超乎想象的，温度必须超过2000华氏度，每平方英寸压力必须至少达到69万磅。为了正确地看待这种压力，一个150磅的人每平方英寸施压大约只有3磅。