lunes, 13 de septiembre de 2010

Vocabulary #10

Mineral:  a solid material of Earth´s crust with a definite composition.



Luster:  the way light bounces off a mineral´s surface.



Streak:  the color of the powder left when a mineral is rubbed against a hard, rough surface.





Hradness:  how well a mineral resists scratching.



Cleavage:  the tendency of a mineral to break along flat surfaces.



Ore:  a mineral containing a useful substance.



Gem:  a mineral valued for being rare and beautiful.



Nonrenewable Resource:  a resource that cannot be replaced within a short period of time or at all.

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