MWJL+4.1

toc

Vocabulary

 * Mineral:** A naturally occurring solid that is inorganic that has a crystal structure and a definite composition.
 * Inorganic:** Not made from living substances or from the remains of living substances.
 * Crystal:** A solid that the atoms are arranged in an exact pattern that keeps repeating itself time after time.
 * Element:** An object created of a single kind of atom.
 * Compound:** A substance when two or more elements are joined together chemically.
 * Hardness:** The level of the minerals calcium and magnesium in water.
 * Mohs Hardness Scale:** A scale ranking ten minerals from softest to hardest to test the hardness in minerals.
 * Streak:** The color of a mineral's powder when scratched.
 * Luster:** The way a mineral reflects light from its surface.
 * Density:** The deepness and mass of a given space.
 * Cleavage:** A mineral's power to break with ease along surfaces that are flat.
 * Fracture:** A way some minerals appear like when the mineral splits in a way that is not regular.
 * Fluorescence:** The feature of some minerals in which it glares under ultraviolet light.

What Is a Mineral?

 * Geologists identified more than 3,000 kinds of minerals.
 * Of all of these minerals, only about 300 are common minerals.
 * About 20 minerals make up most of the rocks of Earth's crust.
 * Naturally Occurring
 * To be classified as a mineral, a substance must occur naturally.
 * Cement, steel, brick, and glass all come from substances found in Earth's crust.
 * However, these objects are man-made.
 * These objects are not naturally occurring, so they are not classified as minerals.
 * Inorganic
 * A mineral must be also inorganic.
 * A mineral can not be made from something that used to be a living thing.
 * Solid
 * A mineral is always solid.
 * The particles of the minerals are packed tightly so that they cannot move.
 * A solid keeps its shape because particles can't move freely.
 * Crystal Structure
 * The particles of a mineral line up in a pattern that repeats over and over.
 * Cleavage and Fracture
 * The way a mineral splits apart can help to identify what mineral it is.
 * Cleavage is a property when the mineral splits along flat surfaces.
 * For example, the mineral Mica separates easily in only one direction, so this mineral has cleavage.
 * How a mineral looks when it breaks in an abnormal or irregular way is called fracture.
 * Special Properties
 * Some rare minerals can be identified by special physical properties.
 * Minerals that glows under ultraviolet light is a property known as "fluorescence"
 * A mineral called Uraninite a few other minerals are radioactive.
 * A few minerals like Quartz have electrical properties.



Back to Homepage