Crystals have been an item of intrigue for thousands of years. Whether admiring them at a jewelers or searching for them in the ground, these shiny wonders of nature draw the attention of young and old. In nature, the amazing objects take millions of years to form in high temperatures and pressures. Now, thanks to the wonders of kitchen chemistry, you can make a veritable crystal garden in your own home. Below are two methods to make beautiful crystals and a brief explanation of how the gardens are formed.
Salt Crystals + Laundry Bluing = Crystal Garden

http://engineering.oregonstate.edu/momentum/k12/june04/index.html

This garden produces very nice, broccoli-like salt crystals from readily available ingredients. They tend to be fragile…but quite beautiful.

Supplies:

• 1 container (per child) – plastic (clear polystyrene) to-go dishes work well
• Several small pieces of porous material to grow on per container – sponges, clay pot pieces, BBQ Briquettes, etc.
• Water
• Ammonia
• Laundry Bluing (such as Mrs. Stewart’s Liquid Bluing…careful it stains!)
• Salt
• 1 small paper cup to mix ingredients (Dixie Cup)
• 1 plastic spoon
• Food Coloring (optional)

1. mixing 2 tablespoons of salt with 4 tablespoons of water, stirring to dissolve as much salt as possible.
2. Next add 2 tablespoons each of ammonia and laundry bluing, again mixing as you go. The mixture will be a blue, watery sludge.
3. Pour the sludge, liquid and extra salt, on top of the porous substrate in the plastic dish. Make sure to get all the salt out of the mixing cup and onto the porous items in the plastic dish (Note: If you use a sponge, wet it first abd squeeze dry for better sludge absorbtion).
4. All the salt may not go into solution; this is okay as long as you pour the extra salt on top of the items in the dish. The porous materials in the dish will not immediately soak up all the liquid; this is okay.
5. The crystals will naturally grow white, like the salt. If you want colored crystals, add a drop or two of food coloring on each item in the dish. The crystals will grow that color.