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Candy Geode Recipe

Candy Geode

Crystallized sugar forms the crystals in this candy geode.

Crystallized sugar forms the crystals in this candy geode.

Geode Candy

Geodes are crystal-filled, hollow rocks. Many rock collectors, children, and geologists delight in finding geodes, which form from gas bubbles in sedimentary rock or in volcanic rock. In the United States, they are most commonly found in the states of Utah, Missouri, Iowa, Indiana, and Kentucky.

Geodes can be hard to find, but simulated geodes are simple to make. This recipe is for an entirely edible geode, made from sugar crystals and chocolate. This candy would be a fun treat at a gem-themed birthday party, science class, or to simply surprise a rock-hound!

Be sure to plan ahead when making candy geodes: the sugar crystals take 2 days to form, so the candy must be made in advance. Make sure you have a space cleared out in a dark cupboard, so the sugar syrup solution has a place to sit, undisturbed, for a full 48 hours. In some cases, the crystals may take more than 48 hours to form.


  • 2 cups water
  • 4 cups sugar
  • food coloring
  • 1 bag white candy melts
  • 2 tbsp unsweetened cocoa powder
  • cooking spray
  • aluminum foil
  • small bowls
  • plastic wrap

Rock Candy Geode Video

How to Make Sugar Crystals (Rock Candy)

The edible crystals inside of the candy geode are made from sugar. As with any other "rock candy" recipe, twice as much sugar as water is required. This recipe will require:

  • 2 cups of water
  • 4 cups of sugar
  • Food coloring (optional)

While food coloring is not required for the recipe, it is highly recommended to create colorful, bright crystals that resemble amethyst and other crystals found in real geodes.

  1. Add 2 cups of water to medium saucepan. Bring the water to a boil.
  2. Add the sugar, one cup at a time. Stir the sugar until it is dissolved.
  3. Remove the syrup from its heat source, and stir in food coloring, if desired.

If several different colors are desired, pour the syrup into 3-4 bowls and add food coloring to each bowl. Tint each bowl of syrup until it is quite dark, as the final crystals will be lighter in color than the wet solution.

Forming the Geode Crystals

The sugar syrup must be poured into foil-lined bowls to create the crystalline interior of the candy geode. For this step in the process, you will need:

  • Small bowls (12 "prep" bowls were used for this recipe)
  • Aluminum foil
  • Cooking spray
  • Simple sugar syrup
  • A dark cupboard

Cut the aluminum foil into squares that will fit inside each bowl. Press the foil into the bowls to create a liner. Spray each foil-lined bowl with cooking spray.

Pour the super-saturated sugar syrup into each bowl. Place the filled bowls into a dark cupboard and allow the solution to sit for 48 hours (2 full days).

Why the Crystals are Made First

Some people might think it would be easier to make the chocolate shell first - why not simply pour the sugar syrup into a pre-formed chocolate shell? At first glance, this appears to be a time-saving measure. Unfortunately, pouring the liquid syrup into a chocolate shell simply won't work: the syrup will dissolve the chocolate! The candy crystals must be made first, and the shell applied after the crystals have dried.

How to Make a Chocolate Geode "Shell"

  1. After 48 hours have passed, remove the sugar solution from the dark cupboard. Pour off the excess fluid. Gently peel the aluminum foil off the sugar crystal form.
  2. Next, melt white chocolate candy pieces in the microwave. Microwave the candy melts in short bursts, 10 to 20 seconds at a time, stirring frequently.
  3. Turn the crystal geode form upside down on a piece of wax paper. Use a paintbrush or a butter knife to gently coat the back of the crystal form in white chocolate. Allow the white chocolate layer to dry.
  4. Add a tablespoon or two of dry, unsweetened cocoa powder to the melted white candy pieces. Adjust the amount of cocoa powder to achieve a brown color.
  5. Paint the brown chocolate layer over the white chocolate layer. Allow the chocolate to dry.
  6. Trim the edges of the chocolate layers with a serrated knife to form an even edge.
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The Finished Edible Geode

Once the candy geode is completed, store the candy in a cool, dry location. Humidity will cause the sugar crystals to disintegrate, and heat will cause the chocolate shell to melt. For a fun gift, wrap the geode in plastic wrap and place a nice label on the package. For a party, display the geodes under a bright light to show off the beautiful crystals!


Leah Lefler (author) from Western New York on July 24, 2017:

It is a really fun candy to make! I hope you are able to try it with your niece and nephew!

Leah Lefler (author) from Western New York on July 24, 2017:

Humidity definitely makes the crystallization process more difficult. We try to do our candy-making in the fall or winter up north - we have humid summers and no air conditioning, which makes sugar crystals difficult!

Peggy Woods from Houston, Texas on May 23, 2017:

It would probably not work well in Houston because of the high humidity here but this was fun to read. I eat very little candy but the photo certainly caught my eye because of the beauty. I do like the beauty of geodes.

Lena Durante from San Francisco Bay Area on April 26, 2017:

This looks really fun. Bookmarking for the next time I have my niece and nephew staying for a few days!

Leah Lefler (author) from Western New York on March 06, 2017:

High humidity can, unfortunately, affect the crystal formation! I hope you managed to make a candy geode, Marisa - my older son loves geology and is fascinated by rocks and minerals. I live in Western NY and we have high humidity in the summer, and I sometimes have difficulty getting decent crystal formation. If you have central air conditioning, that will pull humidity out of the air (we, unfortunately, do not have air conditioning so we are dependent on the forces of mother nature).

Marisa on August 12, 2016:

I'm so excited to make these with my kiddos this week! My second born is obsessed with rocks and geodes- he is going to flip when he sees this. I often find it very hard to include his activites into our family time because he has very specific (and minimal) interests that usually don't allow for any of my other three to enjoy. I can't handle seeing them walk off or get bored because I know it hurts my Nathaniel when they don't like to be a part of his hobbies. But I am positive that this family time will keep all four involved from beginning to end. So THANK YOU for sharing!

My only concern is the humidity aspect of the recipe. Considering the humidity will disintegrate the crystals once the geodes are complete, is it fair to assume that they won't even form if the humidity is too high in the area you store it in for the 2 days? We're in vacation in Maine (as in 5 minutes from the Canadian border, Maine) and for the first time in my life this place is HOT and HUMID. Very humid. And the weather report shows much of the same for the next week or so.

What is your suggestion to try and combat this problem? I'm planning on growing the crystals inside a dark pantry closet. A dehumidifier isn't an option so are fans my only alternative? I'm hoping that you're going to tell me that high humidity only affects the crystals once they're formed but won't interfere with the growing process!

Leah Lefler (author) from Western New York on March 26, 2015:

We really had fun with these, Kristen! They are a little tricky to make (not difficult, just time consuming) - but are very cool to look at and fun to eat!

Leah Lefler (author) from Western New York on March 26, 2015:

Let me know how it works for you! We had fun making them - my boys really loved them!

Kristen Howe from Northeast Ohio on March 19, 2015:

Wow! This is an awesome and clever recipe. The photos are really far out and amazing. Fun to make and delicious to eat. Voted up for awesome idea!

Yoleen Lucas from Big Island of Hawaii on February 21, 2015:

This sounds TOTALLY out of this world! Though I rarely cook, I HAVE to try this! Thanks for posting it!

Leah Lefler (author) from Western New York on September 10, 2014:

We are huge science fans in this house, caseymel - we might as well combine it with our cuisine!

Melanie Casey from Indiana on September 10, 2014:

Wow! Bringing geology and cooking together. Looks tasty!

Leah Lefler (author) from Western New York on September 10, 2014:

Hezekiah, they are really fun. They are a bit messy to eat, though! My kids loved them.

Krystanthe, definitely give them a try! They are really cool to share with the kids, especially if your child loves gems and minerals!

Kathy Hull from Bloomington, Illinois on September 10, 2014:

This is awesome! Going to have to find sometime to try it with my kids, they would love it!

Hezekiah from Japan on September 10, 2014:

Wow these look unreal but I vet they are delicious. My daughter would love these.

Leah Lefler (author) from Western New York on September 10, 2014:

Randomcreative, my boys went crazy for these! They really enjoyed them, and learned about the process of crystallization at the same time.

They are a great project to try at home, DealForALiving! Fairly simple to make, though you do need to make sure you have enough time for the sugar crystals to form (this is the most time consuming part of the process).

Nick Deal from Earth on September 09, 2014:

I know some kids that would go wild seeing something like this and making it at home.

Rose Clearfield from Milwaukee, Wisconsin on September 09, 2014:

This is such a neat idea! I've never seen anything like it before. What a fun project for teachers, parents, and kids alike. Thanks for sharing!

Leah Lefler (author) from Western New York on August 24, 2014:

I love science and thought this would be fun for my children, AliciaC. My boys love geodes (and all things related to geology), so this recipe was a hit in our house!

Linda Crampton from British Columbia, Canada on August 22, 2014:

What an interesting idea! Thanks for sharing the instructions. The results are beautiful.

Leah Lefler (author) from Western New York on August 20, 2014:

My kids really got a kick out of this one - they love gems and minerals, so this was a big hit! I hope you get to try it, Rebecca!

Rebecca Mealey from Northeastern Georgia, USA on August 20, 2014:

This would make an awesome....and delicious science project for kids. Shared and pinned to crafty projects, even though it is food. Thanks!

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