Minerals – Earth’s Jewels SWBAT identify the difference between a mineral and a rock; describe the properties that are used to identify minerals

What is a mineral? Minerals –inorganic, solid materials found in nature. What does inorganic mean? –It was not formed by plants or animals Rock –made up of two or more minerals.

What is a mineral? How do minerals form? –Minerals form from melted rock material, called magma, that cools Precipitation –Water drops out minerals that it cannot hold

Properties of Minerals Crystals –Crystals have an orderly pattern of atoms, arranged in a repeating pattern

Properties of Minerals Cleavage and fracture –How to a mineral breaks Cleavage –Minerals break into smooth planes Fracture –Minerals break roughly with jagged or rough edges

Properties of Minerals Color –This is the least reliable property of minerals. Colors can be misleading (gold and pyrite), and some minerals come in many different colors.

Properties of Minerals Streak –Scrape a mineral across an unglazed porcelain tile and the color it leaves is its streak. Streak does not always match the color Luster –Describes how a mineral reflects light –Shiny, dull, pearly, etc.

Properties of Minerals Hardness –Mohs scale gives the hardness of each mineral –What it can be scratched by shows how hard it is

Properties of Minerals Specific Gravity –Similar to density –Ratio of weight of the sample to an equal volume of water

Properties of Minerals Other properties –Magnetism –Smell –Reaction to chemicals –Visual distortion –Taste

Common Minerals What do we call the common minerals that make up rocks? –Rock forming minerals, which are mostly silicates (they contain silicon and oxygen) Gem –Minerals that are rare and can be cut and polished to give them a beautiful appearance Ore –Minerals that are mined for a profit