Beach in a Bottle

I thought this craft had a lot of potential but didn't like the "cheap" feeling of the plastic bottle, especially with older students in the class.  I wanted something more classy and decided to try using a glass bottle with a cork.  It worked well, although a couple boys pushed the cork in too far.  Thankfully, I had a few extras.  I found the bottles at Michaels.

The first step is to remove the cork!  Using a funnel, pour 1 tbsp of course sand into the glass bottle.  Students were allowed to choose white or black.  Most picked white sand, and there are other colors available at craft stores.  Be sure to use course sand!!!  Fine will mix with the oil and produce an ugly, goopy mess that will have to be thrown out.

Students had the option of adding a small glass white or blue marble and 7 small shells.  Mix 2 drops green and blue food coloring into 2 cups of water to get turquoise.  You could mix other colors such as blue or red.  Tinted water will lighten in the bottle, so go darker than you want.  Fill the bottle half to 2/3s full using the funnel, put on the cork, and swish around.  Carefully dump water out, so most of the sand stays inside.  Pour in fresh tinted water, and repeat.  It will "clean" the sand, getting rid of some of the smaller particles that make the water cloudy.  I figured this out during class when a student noticed my example was clearer than hers.  While experimenting at home, I had emptied my water out several times to try different tints and inadvertently cleaned my sand in the process.

Next, students could add a pinch of glitter.  I had silver, gold, and red to choose from.  Fill bottle almost to the top with mineral oil, again using the funnel.  Rub tacky glue around inside top of the glass lip, just a few millimeters deep.  Press the cork in securely, and wait for glue to dry.  Turn the bottle on its side, and gently rock to create a "wave." 

The glue a little further down the cork may never dry completely and may mix with the water, but I don't think it's a problem.  The cork does a good job keeping the contents inside.  It's more of a precautionary step and probably wouldn't be needed if the students handle the bottle carefully.  Speaking of which, I can't even fathom what a big chore it would be to clean up should one of these break.  The combination of oil, dyed water, and sand isn't good for a carpet!  I emphasized to both students and parents that this isn't a toy.  It should be treated more as a breakable decoration.

Some students opted not to use the oil and instead filled the bottle all the way with tinted water.  This eliminates the "rolling waves" look but still looks pretty.  Another variation is to skip both oil and water and just use sand with the shells on top.  A small piece of paper rolled and tied with a piece of twine would make a fine addition: message in a bottle.  For that version, the shells will stay on top better if fine sand is used.

Tip: test experimental items in the water before adding the oil to make sure you like how they look.  One of my shells floated on the water instead of sinking, which was annoying.  Once the oil is added, you don't want to pour anything out or things get very messy.