When Amanda said, “We should do some geode themed stuff…” I thought, hey, I could really go off the deep end on this one! Afterall, I had never tried to make a geode bath bomb, what could go wrong! Geode anything is currently on-trend, which is awesome because it means you’ll have an instantly recognizable item with a built in market if you decide to sell them. However, on-trend also means that an item or design has been done by tons of other makers. How can you make sure that yours stand out and are different? 

If you’re the only person in your area rocking geode bath bombs that alone might be enough. Amanda’s awesome amethyst bath bombs are sure to catch anyone’s eye and they are some of the most stunning geode bath bombs I’ve seen. If you follow her instructions I’m sure you’ll be selling out of those babies in no time!

If, however, you want to take another swing at the geode game and maybe bring a different twist to it, might I suggest these Heart Geode Bath Bombs?

These were designed using a Cada Mold. It’s actually part of their 7 piece Heart Bombshell Set, which is just stunning. With this mold you create an outer bath bomb shell. The center is left hollow and can be filled with bath bomb dust, crumbles, salts, botanicals, etc. Then you have a stopper that finishes the bath bomb off. When your customer is ready to use the fizzer they can remove the stopper, pour the salts (or whatever you choose to fill the shell with) into the bath, then still have a huge bath bomb to enjoy. 

The 2-part bottom piece of this mold seemed like the perfect way to create a geode! You get a shape with a hollowed out dent in the middle. You still have a nice strong bath bomb too and don’t have to worry about it being too fragile and breaking!   

Now, all that is great, but you might have a little sticker shock when you catch the price of that mold. I can say it’s worth it to me, but that might be a hard one to swallow, especially if you’re just learning to make bath bombs. I completely understand that. If you’re hesitant to take that kind of plunge, you can certainly use a regular tin mold, or vacuum formed mold, press your mix in and dig a little out of the middle the way you’ll see me do with this mold. I can’t say for certain how well this will work as far as keeping your bath bomb nice and strong, but it’s certainly worth a shot. 


Amanda has a great basic recipe for making bath bombs and you can find that here, or use your own favorite recipe!

Bath Bomb Ingredients For Amanda’s Recipe:

  • Baking Soda
  • Citric Acid
  • Cream of Tartar
  • Kaolin Clay
  • Corn Starch, Tapioca Starch or Arrowroot Powder
  • Avocado Oil
  • Polysorbate 80
  • Fragrance Oil
  • Color
  • Mixing bowl
  • Measuring cups/spoons or digital scale
  • Hand mixer
  • Spatula
  • Mold
  • Face mask, gloves and hair net
  • Spray bottle with binder

Many people use pre-mixed Lakes and dyes to get custom colors, but I like mixing my own! To make this gorgeous Ruby Red color with Lakes, I used a 1:1 ratio of Red 40:Red 27 which translated to 1 tsp of each color for a batch that makes 12 full sized bath bombs (6.5 ounce). If your standard batch size is smaller, then start with less colorant at the beginning (you can always add more, but you can’t take it away!) 

Making Bath Bombs:

Step 1: Measure out dry ingredients–except Citric Acid–and thoroughly combine. It’s a good practice to sift your ingredients as you add them to your mixing bowl.

Step 2: Since this batch is a single color, now is a great point to add your Lake or Dye to your dry mix! If you’re using Dyes, you might have already bloomed them in baking soda. If not, incorporate 1-2 microscoops, according to your suppliers recommendations. If you’re using Lakes, press them through a very fine sieve and mix into dry ingredients.

Step 3: In a small, separate container, weigh wet ingredients and blend well before adding to dry mix. 

Step 4: If you’re using a stand mixer you can use a paddle attachment to fully incorporate the wet and dry. If you’re hand mixing, then make sure to continually sift the ingredients, breaking up clumps as you find them. Use a spatula to scrape the sides of your bowl as needed.

Step 5: Once the wet and dry are combined, you can incorporate the Citric Acid. Doing this last helps prevent any accidental reactivity, and helps prevent spotted colors. A good mix will hold its shape when squeezed and dropped.


Begin adding bath bomb mix to your mold. Fill and pack lightly. This isn’t the same as a typical bath bomb mold and you’ll probably need to experiment a bit to find just the right way to fill them.

The reason I say to pack lightly is that next you’ll want to dig the center out a bit, line the indent section up with the outer shell, and press it in as cleanly as possible. If you pressed your mix in too tightly you might not be able to get that indent piece in there all the way which will make your edges crumble where they don’t get packed down. On the other hand, If you didn’t press your mix in firmly enough, it will be too light and will also crumble. You’re looking for that sweet spot–the goldilocks zone!

Don’t get frustrated if there is a bit of a learning curve, these are extremely rewarding when you finally do nail it! Once the indent is pressed in, gently tap your mold with a spoon, and pull the indent section straight up.

Place a piece of bubble mailer or cardboard on the mold, flip the entire piece over and place on a pan or tray. Gently tap again to release the outer shell of the mold. Keep going until you’ve used all of your mix!

You’ll want to make sure your bath bombs are fairly dry before continuing to the next step, preferably 1-2 days.


When the Bath Bombs are dry it’s time to add bath bomb drizzle, colored bath salts, and some paint!


To make a fantastic cocoa butter drizzle that dissolves quickly in the tub, leaves no residue, and hardens really well, I suggest you check out Amanda’s Cocoa Butter Drizzle recipe from her book Bath Fizz and Foam. In lieu of that, you can use just a basic recipe of equal parts melted cocoa butter to baking soda, but be aware that if you don’t incorporate a surfactant or emulsifier, there is the potential for a slippery tub!


To make my colored bath salts I used Epsom salt. I tried other salts, but liked the texture of the Epsom best for these. 

  • 4 tbsp Epsom salt
  • 1 micro-scoop of mica 
  • 5-6 drops of polysorbate 80

Mix the salts, mica and Poly 80 well. Pour some Cocoa butter drizzle into the indent in the bath bomb, make sure the entire area is coated with drizzle.

Sprinkle in the Epsom salts.

If any cocoa butter drizzle comes down the side of the bath bomb it’s a good idea to scrape it off now before it hardens!

If you want your salts to appear white it’s still a good idea to add some mica to give them a shimmery, crystal-like look. For the burgundy I used Thistle from Muddy Soap Co, For the white I used Polar Lights from Muddy Soap Co. For the light pink I used Pink Vibrance from Nurture Soap.


When that has set up a bit you can add the gold mica details. You can use rubbing alcohol, oil, or even polysorbate 80 for painting with mica. For the gold I used Shimmer Gold from Nurture Soap Supplies.  


Let your bath bombs dry for a few more days before packaging! Enjoy creating your Geode Heart Bath bombs and I can’t wait to see your awesome interpretation of this technique! 

Please share on Pinterest! 🙂 Thank you!

About Robyn French Smith

My name is Robyn French Smith! I studied fine art at the University of St Thomas and the Glassell School of Art in Houston TX, and graphic design at The Art Institute of Houston. I started dabbling in DIY bath and body products over 10 years ago after moving to Alaska. While I knew how to make basic soap for several years, I didn’t start looking at it as an art form until about 4 years ago when a neck and shoulder injury made it almost impossible for me to draw and paint. I needed a place for all that creativity to go, and I found it in soap. I received my Basic Soapmaker Certification from the HSCG in 2019 and plan on pursuing further levels of certification.

Find me online at scandaloussoap.com and Facebook!