Minerals Classification Terms (cont)

Fracture terms Conchoidal – Fracture is a smooth curve, bowl-shaped Hackly – Fracture has sharp, jagged edges Uneven – Fracture is rough and irregular Fibrous – Fracture surface shows fibers or splinters

Cleavage A mineral that splits easily along a flat surface has a property called cleavage (ex. Mica)

Cleavage Terms: Perfect - produces smooth surfaces (often seen as parallel sets of straight lines) ex. Mica Imperfect –produces planes that are not smooth ex. pyroxene Non-existent –no cleavage

Perfect Cleavage (Mica)

Imperfect (breaks along a plane but not smoothly) (Pyroxene)

No Cleavage –does not break along a plane --it only fractures (breaks irregularly) (Quartz)

Kyanite

Kyanite –Example Mineral Identification Color: blue/blue grey Hardness (on Moh’s Hardness scale): 4.5 Streak: white Luster: greasy, pearly Cleavage: Perfect Fracture: Fibrous

Answer the following questions (10 points) 1)What are the 5 characteristics that all minerals must have? 2)What does it mean to say that a mineral is inorganic? 3)Amber is a precious material in jewelry. It forms when the resin of pine trees hardens into stone. Is amber a mineral? Explain. 4)Name as many properties as you can think of that can be used to identify minerals. 5)What is the difference between fracture and cleavage?

Look at the Mineral on your table: Answer the following questions about your mineral: 1) What is its color 2) Does it reflect light? 3) Is it heavy or light? 4) How hard is it? If you try to scratch it with your fingernail, does it leave a mark? 5) How does the mineral break? 6) Does the mineral have any other unique properties?