Crystal Growing Mania By Maria and Laura

How fast can crystals grow? Don't they need millions of years? For many people, it's almost unbelievable that you can grow nice sized crystals within a few days or even just hours. Some crystals grow so fast you can literally see how they grow.

When conditions are favorable, each chemical element tends to crystallize in a definite and characteristic form because its molecules are arranged in a unique, repeating pattern. Every crystal has a repeating pattern based on its unique shape. For example, salt tends to form cubic crystals while snow crystals form a six-sided structure.

Many everyday things are made of crystals. Salt, sugar and Epsom salt are all examples of crystals. Look at some sugar under a magnifying glass and you'll see that each grain is the same shape.

How did we become interested in growing crystals?

After our visits to many caverns in Shenandoah Valley, where we have seen many natural crystals, like the stalactites, stalagmites, columns, and flowstone we had many questions about these beautiful natural formations. We became even more interested and curious after seeing the Anthodites, a crystal unique in the world, that have been discovered by Dr. Walter S. Amos at the Skyline Caverns.

The Chandelier also called the "orchid of the mineral kingdom" is the longest Anthodite existing. It is 18 inches long and took 126, 000 years to form. They are a mineral purely made of calcite, and perfectly white, which grew in a vacuum. It 's amazing, but it takes 7, 000 years for an inch to grow.

A simple basic chemical phenomenon explains the formation of a crystal: mixing an acid (liquid) with a base (liquid) you obtain a precipitated salt (solid) + water (H₂O). This also happens with the cavern formations. Carbonic acid (H₂CO₃) is formed by rainwater picking up carbon dioxide (CO₂) from the air and from decaying plants and animals. This reacts with the base Calcium Hydroxide [Ca(OH)₂] forming Calcium Carbonate (CaCO₃) rich water. The calcite crystallizes out of the water and interesting crystals begin to grow.

Our experiment consisted of:

• Dissolving the salt in a teaspoon of tap water.

• Assembling the filter paper tree shaped figure.

• Placing tree in dissolved salt in a room temperature chamber away from touching, jiggling, or air currents.

• Immediately the liquid started to rise through capillarity and tiny crystals started to grow at the ends of the branches.

• We observed the crystals' growth every hour.

• The crystals grew at high speed during the day.

• After the entire mixture at the bottom of the tree was absorbed, and the water evaporated, the crystals left behind formed an amazing pine-tree.

• We repeated the experiment placing the tree at a higher humidity and lower temperature - in the refrigerator.

• Under these conditions the crystals in the refrigerator grew slower than the

crystals at room temperature.

In conclusion dry room temperature air is better for crystals to grow in. Crystals can grow in any light, the pressure and humidity is what changes them. Bibliography

1. Heinz J. Teige: Space Age Crystals. The art and Science of crystal growing -on earth, and in space. 1992

2. Microsoft Encarta Encyclopedia. 2001

3. http://www.caveofthewinds.com: Geology facts. 2002

4. http://www.crystalgrowing.com: Light Speed Crystal Growing. 2002

5. www.Skylinecaverns.com: Skyline Caverns. 2002

6. www.sciencenet.org: Make your own Crystal Garden. 2002

7.http://www.teelfamily.com: Grow a snowflake in a jar. 2002