Rocks and Minerals Study Guide

What are minerals? There are 5 things that characterize minerals. – Inorganic – Solid – Chemical composition – Orderly crystalline structure – Naturally occurring

How are minerals identified? Hardness – how hard a mineral is relative to another mineral Luster – how the surface reflects light Density – the amount of matter in a mineral Color Streak – the color of the powdered form of a mineral Cleavage - when a mineral splits across smooth flat surfaces Fracture – curved or irregular breakage

What are two ways minerals form? Minerals form from… – hot molten rock (magma or lava): When minerals from from the molten rock, it cools and forms the mineral. – the evaporation of hot water solutions: When minerals form from solutions, the solution evaporates, and leaves the mineral behind.

Moh’s Hardness Scale Measures the hardness or scratch resistance of minerals

What can minerals be used for? Jewelry, cosmetics, batteries Hinges, clocks, wiring Mirrors, sporting equipment, light bulbs Watches, pencils, tiles Appliances, matches, containers Furniture, computers, phones

What is the rock cycle? The rock cycle is the natural process in which rocks transform from one rock type into another rock type over time

What are rocks? A naturally occurring solid mixture of one or more minerals that may include organic matter

What processes change rock? Changing temperature and pressure Weathering, erosion, deposition, cementation Melting and cooling

How do rocks form? Igneous rocks form when hot liquid magma cools into solid rock Metamorphic rock forms when rock is exposed to high temperature and pressure and the crystal structures of the minerals in the rock change to form new minerals Sedimentary rock forms when rock is weathered, eroded, deposited, buried,and cemented

Classes and subclasses of rock IGNEOUSSEDIMENTARYMETAMORPHIC Intrusive – magma that pushes into, or intrudes surrounding rock below Earth’s surface and cools very slowly forming large crystals Clastic – forms when sediments are buried, compacted, and cemented by calcite or quartz Foliated – forms when pressure causes mineral grains to align in parallel bands Extrusive – forms when lava erupts and cools on Earth’s surface quickly, forming small crystals Chemical – forms when water evaporates and chemicals crystallizes out of the solution Nonfoliated – no aligned bands; made from one or more minerals; grains or crystals change size or shape or into another mineral Organic – forms from the remains or fossils of once living things