1．diamonds in the united states 
most of the world’s diamonds come from africa，but there is one place in the united states where they are found．it is near murfreesboro，arkansas． 
diamonds were first found near murfreesboro in 1906．about fifty thousand diamonds have come from this field．one forty－caratdiamond was the largest ever found in north america．but most of the stones were too small to make mining worthwhile．soon all mining stopped there．today a visitor to murfreesboro can hurt for diamonds himself． 
a few diamonds have been found in sand and gravel along the great lakes，too．but none of these were in their original blue ground．they may have been formed far to the north and carried south by the last great glaciers． 
1．美国的钻石 
世界上的钻石大部分出自非洲，但美国也有一个钻石产地，它位于阿肯色州默弗里斯博罗附近。 
1906年，在默弗里斯博罗附近首次发现钻石，从这个矿里一共开采了大约5万颗钻石，其中一颗重40克拉的钻石是迄今在北美洲发现的最大的一颗。但是，多数钻石都太小，没有什么开采价值，不久那里的采掘工作就都停止了。今天去默弗里斯博罗的游客可以亲自去寻找钻石。 
在五大湖沿岸的沙地和砾石中也发现一些钻石，但是没有一颗保持原有的蓝色。它们也许是在遥远的北方成形，然后由最后一批大冰川带到南方的。