Reading Comprehension

Read the passage carefully. Then answer the questions below.

Diamonds were formed by being ‘squeezed together’, and according to scientists, this happened about a hundred million years ago. At that time, there existed beneath the ground a mass of hot liquid rock. The earth was in its early cooling stage, and in the process, the mass of liquid rock was subjected to extreme heat and pressure. One of the results was that certain chemical combinations were formed. And one of these was highly crystallized carbon - what we call a ‘diamond’.

Two of the most interesting things about diamonds are their hardness and their brilliance. A diamond is about five times as hard as the next hardest substance on earth. Because a diamond is so hard, getting it ready for use in jewellery is a pretty complicated and skilful process.

First, a diamond is cleaved or divided. This requires a great deal of study to make sure it will split along certain natural lines. A narrow notch is then cut with another diamond having a sharp point. An iron or steel edge is laid on this line, and a sharp blow is struck. If all has been done correctly, the diamond splits instantly in two in precisely the direction desired.

Diamonds also have ‘facets’, or little faces, cut into them. This is done on a high-speed iron wheel on the edge of diamond dust mixed in oil. The average brilliant diamond is cut with 58 facets. All this is done to give the diamond the right shape and brilliance.

Basically, a diamond is a beautiful gem. Its beauty makes it desirable and valuable. The value of one diamond differs from that of another. That is because they vary considerably in colour and quality. They occur in all colours of the rainbow. Some colours are rarer than others. The highest values are placed on those tinged with red or blue and clear, colourless diamonds. Another factor that determines its value is purity. Diamonds may be as pure as a drop of water or may show defects from a tiny pinpoint to a large flaw.

Many diamonds have been so valuable they have played a part in history. Possession of the famous Koh-i-noor (Mount of Light) was so greatly desired by the rulers of Asia that practically all of the conquests of India from 1400 to 1828 were the result of it. The Hope, an unusually blue diamond weighing about 44 carats, has also passed through many hands. The Hope is said to bring misfortune to all who possess it.

Inferior grade diamonds are used in industry. Many are manufactured into diamond-grinding wheels which are used to sharpen tools and to grind lenses. Industrial diamonds are also used in drills by mining companies to drill through rock.