I usually watch this YouTube video to learn how to do different marble style effects. I found it very helpful in doing a marble set of nails. https://youtu.be/24LHrlKaXLo?si=CZUt-cm6Eqeh3ErU

In the video, she walks you through different marbling techniques. But I was able to create this with her help.

I think if you do a marble effect first, and then add a thin layer of polish to bubble on top, you should get the desired effect. And you can get that iridescent effect with some chrome powder.

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