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4.1 Properties of Minerals
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Vocabulary
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 * inorganic-** when a mineral cannot rise from the materials that were once part of a living thing
 * crystal-** when the repeating pattern of a mineral's particles forms a solid
 * element-** a substance made of only one kind of atom
 * compound-** when two or more elements are combined
 * Mohs hardness scale-** it ranks ten minerals from softest to hardest
 * streak-** the color of the mineral's powder
 * luster-** a term used to describe how a certain mineral reflects light from its surface
 * cleavage-** a mineral that splits easily along flat surfaces has this property
 * fracture-** describes how a mineral looks when it breaks apart in an odd way
 * fluorescence-** minerals that glow under ultra violet light have this property

What is a Mineral?

 * any mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition
 * naturally occurring
 * substances found in Earth's crust that are manufactured by people, are not considered minerals
 * inorganic
 * a mineral must also be inorganic
 * solid
 * minerals are always solid
 * crystal structure
 * particles in a mineral line up in a pattern that keeps going on and on
 * this process forms crystals
 * definite crystal composition
 * all minerals have a definite chemical composition
 * almost all minerals on Earth are compound
 * almost all pure elements on Earth are metals

Identifying Minerals

 * Each mineral has their own specific properties that can be used, if needed, to identify it
 * hardness
 * Mohs Hardness Scale
 * Friedrich Mohs invented it
 * it can identify a mineral's hardness
 * a mineral can scratch any other mineral that is softer than itself
 * color
 * minerals can occur in a variety of colors
 * streak
 * a streak of a mineral is the color of its powder
 * a mineral's streak can be different from its appearance color
 * luster
 * luster is the term used to describe how a certain mineral reflects light from its surface
 * density
 * you can measure and compare minerals by comparing their density
 * crystal systems
 * crystals that grow in an open space usually grow almost perfectly
 * crystals that don't grow in an open space are often incompletely formed
 * cleavage and fracture
 * a mineral that splits easily along flat surfaces has the property named cleavage
 * a fracture describes how a mineral looks when it breaks apart in an irregular way
 * special properties
 * some minerals glow under ultraviolet light, so they have a property called fluorescence
 * some minerals are magnetic
 * some minerals are radioactive
 * some minerals have electrical properties
 * some minerals react chemically to acid