EARTHS MATERIALS ROCKS AND MINERALS MINERALS VS ROCKS • MINERAL is a naturally occurring inorganic solid with a crystal structure and a characteristic chemical composition. • These are the building blocks of rocks. • Granite is an example you can see the individual crystals Properties of Minerals • Crystal structure: The arrangement of the atoms. • The difference in the crystal structures between these two minerals offers an idea of the diversity of crystalline forms. Color • Color: Some can be deceptive like quartz. Streak • Streak: Scrape the mineral on an unglazed porcelain plate and observe the color. http://faculty.chemeketa.edu/afrank1/rocks/minerals/streak.htm Luster • Metallic/Nonmetallic Luster The luster of a mineral is the way its surface reflects light. Most terms used to describe luster are selfexplanatory: metallic, earthy, waxy, greasy, vitreous (glassy), adamantine (or brilliant, as in a faceted diamond). It will be necessary, at least at first, only to distinguish between minerals with a metallic luster and those with one of the non-metallic lusters. http://faculty.chemeketa.edu/afrank1/rocks/minerals/luster.htm Density Mass / volume Please see chart on page 667 Hardness • Hardness is the resistance of a mineral to scratching. • Diamond is the hardest mineral with a rating of 10. Fracture and Cleavage • Fracture: how a mineral breaks • Cleavage: a type of fracture where the mineral splits along regular well defined planes. • Do Data analysis pg 667 • Section assessment pg. 669 Rocks and the Rock cycle • • • • • Three major groups of rocks Igneous Sedimentary Metamorphic This is based on how they are formed http://sharksrulescienceiscool.weebly.com/rocks--minerals.html Igneous rock • This rock forms from magma • This forms when molten material cools and solidifies either inside the earth or on the surface. • Intrusive is under the earth, like granite • Extrusive is on the surface of the earth., like basalt Volcanic neck • A volcanic neck is a cylindrical-shaped landform standing above the surface created by magma solidifying in the vent of a volcano. Erosion of the sides of the volcano exposes the neck. • This is a volcanic intrusion that is exposed as the surrounding soil erodes Sedimentary • A rock that forms over time as sediment is squeezed and cemented together. • Three types: • Clastic • Chemical • Organic Clastic Rocks • Made from the broken fragments of other rocks. Chemical Rock • Minerals precipitate out of a solution Iron Ore is a chemical sedimentary rock that forms when iron and oxygen (and sometimes other substances) combine in solution and deposit as a sediment. Hematite (shown above) is the most common sedimentary iron ore mineral. The specimen shown above is about two inches (five centimeters) across. http://geology.com/rocks/sedimentary-rocks.shtml Organic Rock Coal is an organic sedimentary rock that forms from the accumulation and preservation of plant materials, usually in a swamp environment. http://geology.com/rocks/sedimentary-rocks.shtml Metamorphic • Rock change by temperature, pressure or chemical reaction with hot water. • The original rock can be any type. The results is a new type of rock. • It can also have a new mineral content. • A new texture Rock Cycle Rock lab • http://www.rockhounds.com/rockshop/rockk ey/index.html#granite • To help Identify rocks you brought from home. The End