CRYSTALS

What is a crystal? Crystal = a solid in which atoms are arranged in orderly, repeating patterns.

How do we see evidence? Observe the smooth, flat outside surface of the crystal.

Do you think all crystals have smooth, flat surfaces?

Not all mineral crystals have smooth surfaces Not all mineral crystals have smooth surfaces. It depends on how crystals develop (tight space vs. open space) Ex. Rose Quartz

How do crystals form? Crystals form by many processes. Two main processes are: Magma Solutions

MAGMA As magma cools, atoms lose heat, move closer and combine. Atoms arrange themselves into orderly, repeating patterns. The size of the crystals depends on how fast or how slow the magma cools. SLOW = large crystals FAST = small crystals

SOLUTION Crystals can form from minerals dissolved in water. Water evaporates, leaving behind ions that come together to form crystals. OR… If too much of a substance is dissolved in water, crystals can begin to form in the solution.

Magma Solution Labradorite Halite