THEY+4.1

toc =**4.1 Properties of Minerals**=

Vocabulary

 * Inorganic:** An object is not made of living thing or the remains of the living objects.
 * Crystal:** A solid which atoms are arranged in a pattern that repeats all over again.
 * Element:** A substance that is made of a single atom.
 * Compound:** A substance that is made of two or more atoms that are chemically joined.
 * Mohs hardness scale:** a scale that measures the hardness of a rock
 * Streak:** A powder color of a mineral
 * Luster:**How minerals reflects light on their surface
 * Cleavage:** An ability for minerals to split
 * Fracture:** The way how minerals appeal when they split

**What Is a Mineral?**

 * A mineral is a solid with different chemicals
 * There are more than 3,000 minerals in the world
 * Since there are more than 3,000 minerals, there are more probably 3,000 chemicals you need to mixed to make rocks


 * Naturally Occurring**
 * there are many requirements for a rock to be classified as a mineral
 * things such as cement, brick, steel, and glass are not classified as a mineral because of the fact that they are man made objects and didn't particularly form naturally


 * Inorganic**
 * in order for a rock to be classified as a mineral it has to be in organic
 * this means that the mineral can't be formed from an object that was once living


 * Solid**
 * a mineral always has to be solid to keep its shape by squeezing molecules tightly together so none of them could be spread out


 * Crystal Structure**
 * the particles of a mineral lines up in a pattern that repeats again and again
 * sometimes the the crystal structure is obvious to predict that it is a mineral.
 * the only thing that could see a crystal structure is under a microscope


 * Definite Chemical Composition**
 * minerals has certain types of elements in definite proportions
 * Almost all minerals are compounds in which they are made of more than two elements
 * The elements that make up a compound are said to be chemically joined together


 * Identifying Minerals**
 * in California's gold rush in the year of 1849 people were trying to find gold
 * That time they didn't get to find any gold, but instead they were finding minerals that looked exactly like gold
 * The people that time didn't now what to do with the minerals and it was hard for them to identify what they were by only their colors


 * Hardness**
 * You can see if the rock is hard by the Mohs hardness scale
 * Mohs hardness scale invented in 1812 created by Friedrich Mohs
 * To try to test the hardness you have to scratch each rock with each other
 * Color**
 * A color of a mineral is easy to observe
 * But color can be used to identify a few minerals
 * Some minerals can have many colors and some may have only one
 * Streak**
 * Streak is the mineral's powder
 * You can observe the streak by rubbing mineral against a piece of unglazed tile
 * The color of the mineral might vary, but the streak does not
 * Luster**
 * Luster is how the mineral shines in the reflection
 * This is another way to identify minerals
 * Minerals are usually shiny because of metal contained inside
 * Density**
 * Density is the mass in a given space or mass per volume
 * Density is a little bit like how much more heavier a mineral is then another
 * People find out the Density by a weighter


 * Crystal System**
 * crystals of minerals grow atom by atom in order to form the mineral's particular crystal structure


 * Cleavage and Fracture**
 * when a mineral breaks apart that could really help in identifying the mineral
 * cleavage is when a mineral splits easily along flat surface areas
 * Depending where the mineral is arranged depends if the mineral has cleavage
 * when a mineral breaks apart in an irregular way it's called fracture


 * Speical Properties**
 * minerals can also be identified by their physical properties
 * fluorescence is when minerals glow under ultra violet light that has a property