Maximize Crystal Formation (Paul Neumann)

For Alum crystals:

As many egg shell halves for students with some extras for breakage. Explain process on how to blow out eggs.

2-5 lbs Alum (must be aluminum potassium sulfate or won’t make crystals!) Available on-line from Talas.com

School glue, small brushes, water and paper towels to clean up

A way to heat water in measuring cups, a vessel to put shells and saturated alum solution for a day.

Procedure:

For creating alum crystal out of egg shells (will look like an opened geode)

Blow out egg shells

Let them air dry

carefully cut them with a dull knife against your fingers, write student names on bottom

Have students paint them with Elmer's glue

Dust with alum and shake off excess. Let dry

Prepare enough boiling water to cover eggs.

Little by little add capfuls of alum till saturated. (till granules won't dissolve)

Add coloring (even glow highlighter liquid to make them fluoresce)

To make a contrast between the crystals that will cool faster and those slower, put one container into a bath of ice water.

Remove one day later and compare results.

For making bismuth crystals:

Student prior knowledge: Students should be aware that crystals are on our kitchen tables in the form of salt and sugar, in their parents' wedding rings. They are not just for beauty but also have application in industry. Watches and cell phones for example. This experiment incorporates using a paint brush to spread glue and glitter with alum powder as a seed starter for larger crystals to grow. Students may need help if they are awkward using a paint brush.

Explanation: Crystals are compact orderly arrangements of molecular compounds or elements. They result from a variety of means, from heat and compaction to form tight bonds and geometric arrangements or as a result of "sedimentation" as minerals precipitate from richly saturated liquids. Certain conditions will produce larger or smaller crystals or no crystals at all. Crystals will form in a tremendous number of geometric repeating patterns. Water crystals or snowflakes will form in small or large six sided flakes depending on certain conditions. In the case of Gibeon meteorites, that fell in Namibia, the crystals formed over billions of years (older than the earth) creating the fascinating Widmanstattin patterns. These crystals cannot be duplicated in a laboratory. They are very dense, with molecules so close that the iron won’t rust. Compare these to Pallasite meteorites, also made of iron and nickel but have no such pattern but still have an interesting attribute; they hardened with trapped mineral filled gases that formed olivine crystals (peridot-August birthstone). These Pallasite meteorites cooled much faster. In a small way this experiment will explore how the difference in cooling times will affect crystal growth.

Here is a sophisticated explanation and formula from Wikipedia:

"Primary nucleation (both homogeneous and heterogeneous) has been modelled with the following:^[1]