Properties of Minerals

Vocabulary Mineral: naturally occurring solid formed by inorganic process, has crystal structure, definite chemical composition Crystal: repeating pattern of mineral’s particles forming a solid Inorganic: form from materials that were not living Luster: describes how light reflected from mineral surface Streak: color of powder Moh’s hardness scale: used to rank hardness of mineral Cleavage: mineral splits easily along flat surfaces

Vocabulary Fracture: describes how mineral looks when it breaks apart in irregular way Geode: rounded, hollow rock lined with crystals Crystallization: process by which atoms arranged to form material with crystal structure Solution: mixture one substance dissolved into another Vein: narrow channel different from surrounding rock

Defining Minerals Naturally occurring -quartz forms from cooling magma -coal- remains plants tightly squeezed together Solid -definite volume, shape -particles packed tightly -coal, quartz coal quartz

Mineral Properties Crystal structure -repeating pattern -flat sides- faces Inorganic -quartz form naturally as magma cools Definite chemical comp -always contains certain elements -element composed of single atom

Identifying Minerals color- only few have own characteristic color Streak: never varies, distinguishing characteristic Luster: metallic, non-metallic metallic: shiny, reflective Non-metallic: earthy, silky, waxy, pearly metallic Non-metallic

Hardness Rank : softest 10: hardest Determined by scratch test Mineral can scratch mineral softer than itself If it doesn’t scratch- its not hard

Density Mass in given space, pass per unit volume Always same regardless of size sample Mass/ volume Heavier sample- more dense

Crystal Structure Repeating pattern Different minerals- different shapes Halite- cubic Classify by number faces, sides Measure angles at which faces meet

Cleavage, fracture Splits easily flat sheets- cleavage Depends how crystals arranged Mica Fracture- breaks in irregular way Quartz Curved, shell like break mica quartz

How do minerals form Crystals form inside geode Water containing dissolved minerals seep into crack, hollow Form through organic processes Crystallize from materials dissolved in solutions Crystallize as magma, lava cool

Minerals from Solutions Elements, compounds dissolve in water leave solution crystallize Minerals form this way in bodies water on Earths surface Selinite crystals form solution hot water underground

Minerals from Magma and Lava Minerals form from hot magma cooling inside crust Lava hardens on Earth surface Size crystals depends on -rate crystals cool -amount of gas magma contains -chemical composition -rich in silicon, oxygen

Minerals Are Crystalline Geometrical crystal shapes suggest ordered structures.

Minerals from magma Magma deep in surface Cools slowly Larger crystals Quartz Feldspar Tourmaline mica

Minerals from lava Lava on surface Cools quickly No time for large crystals to form Leucite, olivine