Wood Grain Opal Soap - Great Cakes Soapworks Challenge

Wood Grain Opal Soap - Great Cakes Soapworks Challenge

Wood Grain Opal Soap - Great Cakes Soapworks Challenge

The October challenge for The Great Cakes Soapworks Soap Challenge Club is to create a soap that looks like natural wood grain. And wouldn't you know it - the birthstone for October is Opal. So, I chose wood that has become Opalized.

petrified wood with opal matrixThis was my inspiration for the challenge. Petrified wood with an opal matrix. This sort of opal is very rare, and occurs only when wood is petrified at the same time and conditions needed to create the opal. There are only a few places in the world where it has been found, and the specimens are fairly small.


Here are some additional samples of wood grain opal.

 In order to make the concentric rings of a tree, I knew I wanted to do a column pour. However, I didn't want the smooth texture of a round column. So, I found some cardboard used to pack an appliance and crafted my own lumpy column. My idea was that as the soap moved over the uneven top, that the rings would end up being more organic in nature. 

bumpy column for soap pourHere's the column I created from the side and top - but after the first time I tried to use it. (Don't ask, lets just call it a lesson in water discount....)


To mimic the colors of real wood I chose a combination of brown tones. I used walnut hull powder for the darkest brown, from Bulk Apothecarybrown oxide for my medium brown, and some sea clay, which I knew would create a sort of khaki color, both from Brambleberry.

mica wood grain blue sparkleFor my opal I knew I wanted a heavily saturated mica. In my first attempt I tried just one color, and it wasn't as intense as I wanted. So, for this go around, I combined Brambleberry Blue Slushy Mica with NurtureSoap Ocean Blue Flare Mica Powder. Love the shiny!


I mixed all my dry colorants in water before combining my oil and lye in order to keep the colorants from adsorbing moisture and accelerating trace. The brown oxide I keep premixed with sweet almond oil.


wood grain challenge soap scent sea kelpFor my scent I chose Sea Kelp from Rustic Escentuals. The watery greens and deeper vetiver just reminded me of petrified wood. Maybe it was petrified in an ancient sea...

wood grain challenge mixed colorsAfter mixing the colors I had to move fast - so I don't have pictures of the process. What I did was a basic column pour with the three brown colors, but I poured them more around the edge of my bumpy column so they would pick up the variation of texture. And I made fairly small pours so that I could get a lot of "tree rings".

I put the blue mica "opal" in a large squirt bottle, and then went around the rings and squirted inside the soap in places where I thought it looked best. I also treated the inside core of the tree with the blue gemstone.

I think it does a pretty good job of mimicking the real thing. wood grain soap challenge opal

Here's the real stuff again - next to a close up of the wet soap. 

opalized wood 

I was worried about what it would look like once it was saponified. Of course, it's not as shiny, but I think it looks really cool - like a giant piece of wood grain opal.

wood grain challenge slab dry

There was so much water in this mix that it took an extra day before I could cut it. But when I did cut it - wow!

woodgrain opal single barI am very happy with the final product. It was a great learning experience. I haven't done a lot of column pours before, and I learned a great deal while creating my Opal Wood soap.


To do this again, I would re-create my center bumpy column. It ended up being too big to create a lot of lines right in the center of the "tree", and it was a bit taller than I needed. I like the way the tree rings look towards the outside of the mold, and I would love to have more of that look. I think I might also use a brown mica the next time instead of the walnut hulls. The walnut gave me the right color, but the texture did become a challenge with the column. 

woodgrain opal soap cut stack

But, overall, I'm very pleased with the results - and it was a lot of fun! Thanks Amy Warden from Great Cakes Soapworks for organizing the challenge, and thanks to Modern Soapmaking and Brambleberry for being sponsors! 


  • Michelle Rogerson: October 17, 2016

    What a great inspiration – and a great interpretation of it! I hadn’t thought of petrified wood, and you did a beautiful job of translating it into your soap. :)

  • Debi Olsen: October 16, 2016

    I love the colors and the creativity you put into this, Susan! Well done!

  • shauna veilleux: October 15, 2016

    Wow. I’m a bit of a rockhound so I knew exactly what you had mimicked before I even got to your blog post. It looks beautiful. I want to string it on a cord and wear it as a pendant :) Great job, love the color choices!

  • Belinda: October 15, 2016

    Beautiful colours – what an inspiring soap, Susan. Well done and congrats on a great entry into this month’s soap challenge. Thanks so much for sharing your process too :)

  • Amy Warden: October 15, 2016

    Very creative idea, Susan! Love the inspiration and the final outcome. I think you’re definitely on the right track with your “bumpy” column. Great job!!

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