MINERALS AND CRYSTALS AUGUST 24, 2016

Why do materials glow in the dark? Fluorescent materials – materials that have the ability to absorb invisible ultraviolet light and change it into light you can see.

Minerals What are they?

Defining a Mineral? There are requirements… must be natural not made by humans must be inorganic cannot be made from living tissue or remains of someone that was once living must be a solid not liquid or gas must have a definite chemical makeup example: salt is a compound made of the elements sodium and chlorine must have crystal structure

Crystal??? What is it? In a crystal, the atoms or ions in a substance are arranged in an orderly pattern that repeats over and over again.

Remember…. A material must possess all five of these characteristics to be classified as a mineral.

Crystal Formation Two ways that crystals may form… Some form when melted or partially melted rock cools on or beneath Earth’s surface.

Crystal Formation Two ways that crystals may form… Some form when minerals dissolved in water are left behind.