Geode Moon Block : 10 Steps (with Pictures)

While this by no means is a real geode or moon rock, with a few supplies you can make your own unique block! You will need a few things to start with:

Foam Core
Exacto Knife/Box Cutter
Ruler
Pen
Hot glue
Rockite (available at Ace Hardware)
Balloons, I used standard party balloons and squiggly ones
Blue tape
Microwave
Microwave/Heat Safe bowl or cup
Glycerin (available at Michaels)
Food coloring or soap die

Step 1: Step 1: Cut Out Form

First we need to make a form for our rockite to cure in. I used my foam core, measuring instruments, pen, and knife to mark where I need to cut. My form measures 2 in x 3 in x 6 in, but I don't want to fill the form all the way to the rim. I marked an additional line at 1.5 in. This will be your fill line for the rockite.

Step 2: Step 2: Assemble Form

With our pieces cut out and marked, assembly the pieces into a box, leaving the top open. Using the hot glue, make sure to seal all the edges. I also used blue tape to make sure there were no leaks. I also added an additional small ledge to better indicate my fill line. This will help when the balloons are added to the form work.

Step 3: Step 3: Blow Up Balloons!

Blow up the balloons! The more balloons you have, the more holes and craters you will have. Do not blow the balloons all the way up, just enough to get some air and minor size variety.

Step 4: Step 4: Arrange Balloon in Form

Once the form is dry and balloons are inflated, place the balloons in the form work. You want the balloons to touch each other and the edges of the form for more of a moon pattern. However, if they are packed too tightly you run the risk of the mould cracking when removed from the form work. The balloons will not stay in the form on their own, so add blue tape to keep them in place. Be sure to leave space to see your fill line/ledge, and the be able to fill the form. Since my scale is smaller, I limited myself to 3 strips over the balloons and form.

UPDATE: Make sure the tied portion of your balloon is not cast in the rockite. The balloon will become stuck and you will have plastic embedded in the final block.

Step 5: Step 5: Prepare Rockite

Rockite is similar to concrete and plaster, with a much faster set time. When mixed properly, rockite will set in 15 minutes and cure in about 25. Add a scoopful of rockite (I used a small paper cup), and SLOWLY add water. The rockite should be the consistency of pancake batter. If the mix is too watery, the rockite will not set of will have a layer of water on the top. If it is too dense, the mix will not pour into your mould properly. Mix in small amounts, you will need less rockite than you think, and if you do not mix enough you can do a second pour. Do not stop mixing the rockite, once the rockite stops being stirred it starts to set.

Step 6: Step 6: Pour Rockite Into Mould

Pour the mixed rockite into the mould. Gently tap the sides the work out an air bubbles and be on the lookout for leaks. Any leak can be repaired with more hot glue. Let rockite set. The rockite will get hot, this is the curing process, and once warm the rockite will soon be ready to be removed from the mould. The longer the rockite sits in the the mould, the more debris adheres to the rockite from the foam core.

Step 7: Step 7: Remove Mould

Once the rockite is cured, remove the mould. The foam core will stick to the rockite. This is easily removed by rubbing the rockite. Do this over a trash can, the foam core leaves a layer of paper on the rockite and can be messy when removing. Next pop the balloons. Once the balloons are popped, they should pull out of the rockite. They may have to be cut into smaller pieces. For some of the balloons, I used tweezers to pull them out of the rockite. Be careful not to crack the rockite while removing the balloons. Most adhesives do not stick to rockite, so if a piece breaks off chances are they will not reattach.

Step 8: Step 8: Prepare Glycerin

Glycerin is the material used when making home made soap. Cut the glycerin in small chunks, place in a microwave safe bowl/cup, and cook until liquid. Cooking times will be provided on the package, and may be specific for each brand. I did not have a microwave, so I used a solo cup and boiling water to heat the glycerin (I would not recommend this, it takes much longer). Add in the food coloring/soap die. I added in two drops of die because I wanted a lighter shade of purple. The more die, the darker the color. Color and intensity are up to you.

Step 9: Step 9: Pour Glycerin

You will have to work quickly, glycerin can start to set in minutes, and will be fully set in under an hour. Seal all the holes in the rockite with blue tape, and pour glycerin in a few of the holes left by the balloons. Carefully rotate the rockite to spread the glycerin around. If you want glycerin to pool more in one area than another, either set down the rockite or hold it so the warm glycerin moves to the desire location. The glycerin dries relatively quickly once in the rockite. Wait for about 10 minutes, then remove blue tape. Remove any excess glycerin that may have seeped through the the seal, or any unwanted glycerin from the pores of the rockite. Once all the glycerin is set, you are finished! Now you have your very own geode moon block.