Some of the earliest diamonds
1 from India. In the eighteenth 2
they were found in Brazil (巴西), and in 1866, large deposits
(矿石产地，矿床) were found 3 South Africa.
Now Africa 4 nearly all the world’s
crude (未经加工的) stones which can become 5 later. Until diamonds are 6 and
polished, they do not shine like those you see on a ring—they just 7 like small, blue-grey stones.
Diamond itself is the only material 8 enough to be cut and polished into diamonds—though recently, light beams
9 lasers have been developed which can
bore (穿) holes in diamonds. A fully cut "shining" diamond has 58 faces (表面，平面).
A place in Holland (荷兰) and a place in Belgium (比利时) have been the centres of
the diamond cutting and polishing industry 10
seven centuries.