Page 170 - PDF_Oxford Grammar for Schools 5_Neat 1

Look at the sentences below about coal and diamonds. Read the text to decide if the sentences
are true or false.

ÿ Most diamonds aren't used injewellery, true /false
1 There are diamond mines and coal mines in India, true /false
2 26,000kg of diamond ore is extracted from the ground every year, true / false
3 Diamond miners use X-ray light to identify diamonds in diamond ore. true / false
4 More coal than any other fuel is burnt to generate electricity, true / false
5 Diamonds are formed from coal, true / false
6 Coal and diamonds both contain the element carbon, true /false
7 The arrangement of carbon atoms is the same in coal and diamonds, true / false
8 Volcanic eruptions often throw out diamonds, true /false
9 Very high temperatures are needed for coal to form, true /false
10 Fossil fuels are formed from carbon and ancient organic material, true / false

Diamonds and coal Are diamonds formed from coal?

Inthe past, people believed that diamonds were
formed from coal. Geologists now say that this isn't

Diamonds true.
The element carbon is found in both coal and
Diamond is a very hard and pure substance. Only diamonds, but the carbon atoms are arranged
20% of diamonds are used injewellery. The other differently incoal and diamonds.
80% are used in industry for cutting and other
purposes. Also, although it takes millions of years for coal and
diamond to form, they are formed in different ways.
Most diamonds are mined in Central and Southern
Africa, Canada, India, Russia, Brazil and Australia. How are diamonds and coal formed?

About 26.000 kg of diamonds are mined everv year.
V V»».
* J Diamonds were termed over millions ot years
A V»V MV J W V V V4» V *«•( VM V >
Diamond ore - rock which contains diamonds - is deep below the surface of the Earth, at very high
taken from the ground. The diamonds are identified temperatures and at very high pressure. They were
in the ore with X-ray light. Finally, the ore is then thrown out onto the surface of the Earth by
crushed to reveal the precious stones. volcanic eruptions. At that time, the Earth was
hotter than it is today.

Coal is formed over millions of years, by the
Coal is a black rock which is burnt to produce compression of layers of rock and mud. Like oil, it
energy for electricity.
contains ancient organic material from plants and
More than five billion tons of coal are mined each animals as well as carbon. For this reason coal is
year. There are coal mines in China,the USA, India. often referred to as a 'fossil fuel'.
Australia, Russia and many other countries.
Coal is the largest source of energy
for electricity inthe world. '

170 Revision 8 Exam preparation