Page 220 - New Medley 5 Semester 2

 Gneiss: It is formed from granite which is an igneous rock.

In this rock, mineral grains get attened due to tremendous
heat and pressure, and get arranged in alternating patterns.

ey have a glittery appearance because they contain a

shining mineral called mica.

Gneiss
1 • Remembering

Fill in the blanks.

1. e study of the earth and its life is called .

2. Rocks are found in the earth’s .
3. Igneous rocks are also called .

MINERALS

e earth is made up of di erent types of materials, which are further made up

of one or more elements. Some of these elements are found in pure form and
others in the form of compounds. An element or a compound found in the

earth’s crust is called a mineral.

Metallic and Non-metallic Minerals

Rocks contain many useful minerals.
 e minerals containing metals are called

metallic minerals. e minerals from which Diamond Sapphire
metals can be extracted pro tably are called

ores. Iron, copper, gold and aluminium are
extracted from their ores.

 e minerals that do not have metals in

them are called non-metallic minerals. Emerald Ruby
Some of these are in the form of crystals. Some gemstones

ey are hard and can be polished to make

gemstones. Common gemstones used in Knowledge Zone

making jewellery are diamond, sapphire, Diamond is the hardest substance.
emerald and ruby. It is a non-metallic mineral.

218