4/14 聽力高機率考題分享
Black diamond/ Carbonado 黑鑽石
可能考的重點：
一. 名字由來及特性
Carbonado名字的來源是葡萄牙文 porous charcoal(多孔的黑碳)，多孔即是
黑鑽石的其中一個特性。 雖然叫鑽石，但他的硬度過硬無法切割，所以也無
法形成我們一般可用的珠寶或鑽石。
ABOUT CARBONADO: The term "carbonado" was coined by Portuguese in
Brazil in the mid 18th century because it resembles porous
charcoal. Carbonado diamonds are so tough that it took a 20-ton
hydraulic press to break one. This means it is almost impossible
to work carbonado into jewelry settings, since they are too hard
to be polished or cut -- except with another carbonado. They get
their hardness from their structure. While conventional diamonds
are cut from a single crystal that breaks easily along a natural
line, carbonados are made of millions of small crystals stuck
together. Carbonados were first used to polish Brazilian hardwood
before transporting it to Europe. In 1905 it was used to drill the
rocks for the Panama Canal.
二. 來源
光譜顯示黑鑽石可能來自小行星撞擊地球而成。
目前一般地球上常見的鑽石是在很深的地底下形成，而且是由兩次火山爆發
噴發到地表（約一千萬年前及十億年前）才變成我們可獲取的鑽石。黑鑽石
超過38億年以前產生的，顯然跟一般鑽石形成的方式不一樣。
Carbonados, or black diamonds, have long been a mystery. They're
the oldest, toughest and rarest diamonds around. Now, some
researchers have a theory about its origin, and it's out of this
world, literally.
Stephen Haggerty, Ph.D., a geoscientist at Florida International
University in Miami, has been studying black diamonds for more
than a decade. It's a challenge because researchers are still
trying to figure out where the black diamonds came from.
Traditional diamonds are formed deep in the earth and came to the
surface through two volcano eruptions that happened 100 million
and one billion years ago. Carbonados are older than 3.8 billion
years. They clearly did not form in the same way that conventional
diamonds formed.
The origin of carbonado -- more popularly known as black diamond
-- have long been a mystery to scientists.
但也有其他科學家覺得黑鑽石來源可能來自超新星(supernova)
New analysis of the world's toughest diamonds suggests they might
have come from outer space, specifically from a star that exploded
long ago, called a supernova. Researchers from Florida
International University believe carbonados came from a large,
diamond-bearing asteroid that may have fallen to earth billions of
years ago, when the earth and moon were being heavily bombarded
by space rocks.
三. 分布
多數地球上的鑽石到處都找的到，但是黑鑽石目前只在巴西及非洲兩個國家
可找到蹤跡。
Most diamonds can be found all over the world, but carbonados are
only found in Brazil and Africa. Dr. Haggerty believes black
diamonds came to earth during an asteroid event that struck when
the two countries were still one continent.
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