Geode Bath Bombs: How to Make Bath Fizzies with Crystals Inside
Learn how to make DIY geode bath bombs with a beautiful crystal structure and elegant gold rim! Geode bath bombs are easier to create than you think. They also make spectacular homemade gifts. In this tutorial, I’m sharing all my best tips and techniques for making bath bombs at home.
What Are Geode Bath Bombs?
A couple of years back, I shared a fun geode soap recipe and thought it was time to create a geode bath bomb tutorial as well. But wait a sec! What exactly is a geode bath bomb? Geode bath bombs mimic the look of real geodes, which are hollow rocks studded with colorful crystals inside.
Creating DIY geode bath bombs might seem complicated, but I’ll show you a super simple technique that will result in stunning crystal bath bombs every time.
Once you have a bunch of geode bath bombs, why not turn them into handmade gifts for your friends, coworkers, or kids’ teachers? Everyone will appreciate a homemade wellness gift. Especially when you pair these bath bombs with other treats, like these relaxing lavender shower steamers or my luxurious coffee body scrub. So, whether you want a luxury at home spa day or decorative bath time treats you can gift to friends and family, this project has you covered!
Materials & Supplies
These geode bath bombs have two main components: the bath bomb mixture consisting of baking powder plus citric acid, and coarse sea salt to represent the crystals. Let’s go over each bath bomb ingredient in more detail:
- Baking soda and citric acid are responsible for the fizzing reaction. Both lose their potency over time, so be sure to work with fresh ingredients.
- Cornstarch bulks up the recipe and lightens the texture. Adding cornstarch helps the geode bath bombs float instead of sinking to the bottom of the tub. (If you prefer not use cornstarch, arrowroot powder is a suitable substitution for this recipe.)
- Epsom salts are rich in nourishing magnesium and other trace minerals. I like to add Epsom salts for the added skincare benefits.
- Coarse sea salt is how we’ll achieve the crystal look that is typical for geodes. For a nice crystallization, get the coarsest sea salt you can find.
- Mica powder is needed to tint the bath bomb mixture and salt crystals. I opted for bright pink, but you can create your homemade geode bath bombs in any color desired.
- Liquids: You’ll also need sweet almond oil and water to moisten the bath bomb mixture.
- Gold glitter is combined with a small amount of rubbing alcohol to make gold paint. I adorned each bath bomb with a gold line edge to accentuate the elegant appeal.
- Bath bomb molds: I used the medium size from this set of 3 and got 4 bath bombs from the recipe. The yield will vary if you choose the larger or smaller molds.
- Mixing bowls and whisk to create the bath bomb mixture and color the sea salt.
- Paintbrush: A soft, round paintbrush is needed to paint on the gold line.
How to Make Geode Bath Bombs
There are two key elements to making perfect geode bath bombs: For one, you need to get the just texture right. And then it’s all about how you fill the bath bombs molds. From there, everything else is pretty simple. Let me explain the process step-by-step:
#1: Make bath bomb mixture
In a large mixing bowl, add the baking soda, citric acid, cornstarch, and Epsom salts. Stir in 1.5 tablespoons of pink mica powder. Then mix until the color is solid.
Next, pour the sweet almond oil and water into a small jar. Seal tightly with a lid and shake vigorously to combine the ingredients.
Now very slowly pour the liquids into the dry baking soda mixture. Be sure to whisk continuously while you pour as to not activate the fizzing reaction. Mix until the mixture is moistened and has the consistency of damp sand.
#2: Color the sea salt
In a separate bowl, add the remaining 1/2 tablespoon mica powder to the coarse sea salt. Mix together until the salt crystals are completely tinted.
#3: Fill mold and shape bath bombs
Overfill one half of a bath bomb mold with the bath bomb mixture. Now add ¼ of the sea salt to another half of a bath bomb mold. Then overfill with the bath bomb mixture. Press the two overfilled bath bomb molds together and gently twist.
#4: Let dry
Allow the bath bombs to set in a dry location for 3 to 4 hours or overnight.
Once dry, unmold the bath bombs by carefully lifting one of the bath bomb molds and then removing the other half. Gently dust of any sea salt that didn’t stick.
#6: Paint geode bath bombs
As a finishing touch, mix the rubbing alcohol and edible glitter in a small bowl. Then using the paintbrush, paint a gold line around the edge where the sea salt meets the bath bomb for a decorative look. Your DIY geode bath bombs are ready to give as homemade gifts or enjoy at bath time for a DIY spa day at home.
Tips for Perfect Geode Bath Bombs
Before you get started on how to make your own geode bath bombs, read through my helpful tips and tricks for success.
- Add the liquids slowly: Pouring the liquids too quickly into the dry ingredients can cause a reaction. So be sure to add the almond oil and water slowly and stir continuously.
- Adjust the texture: Depending on your ambiance, you may need slightly more or less liquid. Remember, the texture should resemble barely damp sand and not be too wet.
- Let the bath bombs dry in the mold for a few hours before unmolding: I found that it’s best to let the bath bombs dry in the molds for a few hours before demolding.
- Dealing with high humidity: Humidity is notorious for hindering the drying process. If you live in a high-humidity area, try to find the driest place in your home. If possible, let the bath bombs dry in front of a dehumidifier.
- Scent the bath bombs: If desired, fragrance your bath bombs with essential oils or fragrance oils. To do that, mix the almond oil-water mixture with up to 40 drops essential oils and then add the scented oil to the dry mix.
If you still need help, you can find more tips for making bath bombs here along with an easy no-fail, shea butter bath bomb recipe. You’ll also learn how to formulate a bath bomb recipe from scratch in addition to information on using ingredients such as Polysorbate 80 to keep any oils or fragrances from floating on top of the water.
How to Use Geode Bath Bombs
You use geode bath bombs like you would use any other bath bombs. First, fill the bath with warm water. Then add the bath bomb and watch it dissolve and color the water. The Epsom salt and sea salt crystals need a few moments longer to dissolve. Swirl the water with your hand to speed up the process.
Since the bath bombs contain almond oil, the bathtub may be slippery. Please be careful when getting in and out of the tub.
How to Store Bath Bombs
- Storage: To ensure your bath bombs stay fresh and fizzy, store them in an airtight container in a location protected from moisture and humidity. I keep mine in a cupboard. Also, I like to wrap each geode bath bomb in plastic wrap to offer even more protection from moisture.
- Shelf life: The finished DIY geode bath bombs should last for at least 1 year or longer when stored properly.
- ½ cup baking soda
- ¼ cup citric acid
- ¼ cup cornstarch
- ¼ cup Epsom salts
- 2 tablespoons sweet almond oil
- 1 teaspoon water
- 1 tablespoon coarse sea salt
- 2 teaspoons deep rose mica powder
- 50 squirts gold edible glitter
- 1 teaspoon rubbing alcohol
- Bath bomb molds
- Small paintbrush
- Mixing bowls
- Whisk the baking soda, citric acid, cornstarch, and Epsom salts together in a large bowl.
- Once combined, stir in 1.5 tbsp of mica powder. Mix until the color is solid and evenly distributed throughout the dry ingredients.
- Now add remaining ½ tsp of mica powder to the coarse sea salt. Stir until the color is solid.
- Pour sweet almond oil and water into a small jar with a lid. Shake well to mix.
- Then very slowly pour the liquid into the baking soda mixture. Whisk the ingredients the entire time, so as not to activate the bath bombs.
- Overfill one half of a bath bomb mold with the bath bomb mixture so it's piled high, but not packed into the mold half.
- Then add ¼ of the sea salt to the other half of a bath bomb mold. Overfill the other side with the bath bomb mixture the same as the first.
- Now firmly press the two overfilled bath bomb molds together so the sides line up. Then gently twist.
- Set the bath bombs aside. Then repeat with the remaining mixture until all the geode bath bombs have been made. Once complete, allow the bath bombs to set for 3-4 hours prior to unmolding.
- Once unmolded, lightly dust off any of the sea salt that didn’t stick to the bath fizzies.
- Finally, mix the rubbing alcohol and edible glitter together in a small bowl. Then use a paintbrush to paint a gold line around the edge where the sea salt meets the bath bomb to complete your creations.
If desired you can substitute the water called for in the recipe with witch hazel. Alternately, you can use Polysorbate 80. (This ingredient is used to make oil water soluble. It prevents the oils in bath bomb recipes from floating on the surface of bath water.)
You can substitute the edible gold glitter in this DIY with gold mica mixed with rubbing alcohol instead for the same effect.
More Bath Bomb Recipes
For some other beautiful DIY bath bomb recipes, be sure to try one of the following projects for more fizzing fun:
- Chocolate Chip Cookie Dough Bath Bombs
- Bath Bombs with Shea Butter
- Unicorn Cupcake Bath Bombs
- Epsom Salt Bath Bombs
- Easter Egg Bath Bombs
- Hidden Rainbow Embeds for Bath Bombs
- DIY Bubble Scoops
- DIY Bubble Bars
I hope you loved learning how to make bath bombs for a fun spa day at home or creative homemade gifts. For more fun bath and body recipes, be sure to follow me on your favorite social networks. You can find Soap Deli News on Facebook, Twitter, Pinterest, and Instagram. Or subscribe to my newsletter.