VOA慢速英语2018 新报告揭秘稀有蓝钻的历史（在线收听）

New Report Shares Secrets of Rare Blue Diamond’s History

The Hope Diamond is one of the world’s most famous jewels. It was in the possession of a series of people: kings, bankers, rich women and thieves, before its arrival 60 years ago at the Smithsonian Institution in Washington, D.C.

希望之钻是世界上最著名的珠宝之一。它辗转经过了许多人的手，有国王、银行家、贵妇和小偷。之后，它于60年前来到华盛顿特区的史密森学会。

A rare blue diamond, it has a complex social history, to be sure. But, far more so is its geological history, researchers say in a new report.

一颗罕见的蓝色钻石，无疑有着复杂的社会历史。但研究人员在一份新报告中指出，其地质历史更是如此。

“This is the first time anyone has come up with a fact-based study or model for how blue diamonds form,” said Gemological Institute of America research scientist Evan Smith. He led the study published in the journal Nature.

“这是第一次有人针对蓝色钻石是如何形成的，而提出基于事实的研究或模型。”美国宝石学院研究科学家埃文·史密斯说道。他负责这项发表在《自然》杂志上的研究。

The group looked at 42 blue diamonds, including one from South Africa that recently sold for $25 million in 2016. Researchers could tell where the stones were formed based on the very small minerals trapped inside.

科学家们分析了42颗蓝色钻石，其中包括一颗来自南非，在2016年售价为2500万美元的蓝色钻石。研究人员可以根据钻石里面非常小的矿物质来判断这些宝石形成的位置。

The scientists found the gems can form at least 660 kilometers below the earth’s surface, in a part called the lower mantle.

科学家们发现，这些宝石能形成于至少660千米的地下深处，在一个被称为下地幔的部分。 

Diamonds are a hard, clear form of pure carbon called a crystal. They form under extreme heat and pressure. The report says that blue diamonds crystallize alongside water-bearing minerals that long ago were part of the floor of the sea. But these minerals were pushed deeper underground during the movement of large tectonic plates that shape the Earth’s surface.

钻石是一种坚硬透明的纯碳形式的晶体。它们在极端高温和高压下形成。该报告指出，蓝色钻石与含水矿物一起结晶，这些含水矿物很久以前就是海底的一部分。但在塑造地球表面的大型板块运动过程中，这些矿物被推向地下深处。

Scientists already knew these diamonds received their blue color from the element boron. The study says that boron had once been in ocean water but was eventually pushed into the seafloor rock. Over millions of years, the boron continued to move deep underground.

科学家们已经知道这些钻石是从硼元素中获得蓝色色调的。该研究表明硼曾经存在于海水中，但最终被推入了海底岩石中。数百万年来，硼继续向地下深入移动。

Many diamonds appear colorless. Often, however, they have some yellow color. Still others have a light brown, pink or green color. About 99 percent of all diamonds form somewhere between 150 to 200 kilometers underground, a far shallower birthplace than their blue relations.

很多钻石看似无色。但它们通常会有点黄色。 有些钻石还会是浅棕色、粉红色或绿色的。大约99％的钻石形成于地下150千米至200千米处，这比蓝色钻石的形成地要浅得多。

“These diamonds are among the deepest ever found,” Carnegie Institution for Science geochemist Steven Shirey said of the blue diamonds.

“这些钻石是迄今为止发现的形成位置最深的钻石，”卡内基科学研究所地球化学家史蒂文·夏雷在谈到蓝钻时说道。

The public can see the Hope Diamond at the Smithsonian National Museum of Natural History in Washington D.C.

在华盛顿特区的史密森尼国家自然历史博物馆，民众可以看到希望之钻。