Minerals Chapter 3

Properties of Minerals Section 1

Big Question What is a mineral?

What is a mineral? A mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition. Naturally occurring – it is formed by processes in the natural world. Inorganic – it cannot be formed from materials that were once part of a living thing.

What is a mineral? Solid – the particles that make up a solid are packed together very tightly so that the mineral has a definite shape and volume. Crystal structure – the particles of a mineral line up in a repeating pattern. Definite Chemical Composition – a mineral always contains certain elements in definite proportions.

Big Question How are minerals identified?

How are minerals identified? Minerals are identified using the characteristic properties of color, streak, luster, density, hardness, cleavage and fracture, and crystal systems. Color Streak – the color of its powder Luster – the term used to describe how light is reflected from a mineral’s surface. Density – mass in a given space, or mass per unit volume.

How are minerals identified? Hardness Moh’s hardness scale Hardness can be determined by a scratch test. Crystal Systems – geologists classify crystal structures into six groups. Cleavage and Fracture Cleavage is the property of a mineral that splits easily along flat surfaces. Fracture describes how a mineral looks when it breaks apart in an irregular way.

Special Properties Fluorescence Magnetism Optical Properties Reactivity

How Minerals Form Section 2

Big Question What ways can minerals be formed.

What ways can minerals be formed. Minerals can be formed from magma, lava, and solutions.

How do minerals form from magma and lava? Minerals form as hot magma cools inside Earth, or as lava hardens on the surface. When these liquids cool to a solid state, they form crystals. Magma is molten material from inside Earth that hardens to form rock. Lava is magma that reaches the surface. Lava also forms rock when it cools and hardens.

How do minerals form from water solutions? Minerals form from water solutions when elements and compounds are dissolved in water and crystallization occurs.

Using Mineral Resources Section 3

Big Question How are minerals used?

How are minerals used? Minerals are the source of gemstones, metals, and a variety of materials used to make many products. Gemstones are hard, colorful minerals that have a brilliant or glassy luster.

Big Question How are ores processed to obtain metals?

How are ores processed to obtain metals? To produce metal from a mineral, a rock containing the mineral must be located through prospecting and mined, or removed from the ground. Then the rock must be processed to extract the metal. Prospecting – observing rocks on the land surface and studying maps of rocks beneath the surface to find ore deposits. Mining Smelting – an ore is mixed with other substances and then melted to separate the useful metal from other elements the ore contains.