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Minerals are all around us 2.1 – MINERALS ARE ALL AROUND US 2.2 – A MINERAL IS IDENTIFIED BY ITS PROPERTIES 2.3 – MINERALS ARE VALUABLE RESOURCES Minerals are all around us Minerals have four characteristics A mineral is a substance that: Forms Is in nature a solid Has a definite chemical makeup Has a crystal structure 2.1 Minerals are all around us. mineral formed in nature solid element crystal A mineral has four characteristics. crystal structure cubic 2.1 Minerals are all around us. formed in nature solid mineral chlorine element crystal A mineral has four characteristics. definite chemica l makeup crystal structure sodium halite Minerals are different from Rocks: A mineral must have the four characteristics. A rock has only two, it is a solid and it forms naturally. 1. Forms in Nature: Minerals formed by natural processes. The mineral halite (table salt), forms when water evaporates in a hot, shallow part of the ocean, leaving behind the salt it contained. 1. Forms in Nature: Many types of minerals, including the ones in granite, develop when molten rocks cool. 1. Forms in Nature: Talc, a mineral that can be used to make baby powder, forms deep in Earth as high pressure and temperature cause changes in solid rock. 2. Mineral is a solid A mineral is a solid, it has a definite volume and a rigid shape A Liquid or Gas is not a mineral 3. A Mineral has Definite Chemical Makeup. It consists of specific combination of elements. An element is a substance that contains only one type of atoms. 4. A Mineral has a crystal Structure: A crystal is a solid in which the atoms are arranged in an orderly, repeating threedimensional pattern. DIAMOND AND GRAPHITE Both consists of one element -Carbon. The arrangement of the carbon atoms are not the same, so they have different structure and properties Diamond is extremely hard , graphite is soft and dull. DIAMOND AND GRAPHITE Minerals are Grouped according to Composition Scientist classify minerals into groups based on their chemical makeups. The most common group is the silicates. All the minerals in this group contain silicon and oxygen joined together. Rock forming Minerals: Only 30 minerals make up most rocks in the crust. That is why they are called rock-forming minerals. Silicates, make up 90% of rocks on Earth’s crust. They are the most common Rock forming Minerals ( silicates: silicon and oxygen) Second most common group of rock-forming minerals is the carbonates. All minerals in this group contain carbon and oxygen joined together on rock- forming minerals.