Vectorized rock texture on blue circle

I created this while learning about how to make custom textures from photographs in a tutorial by Spoon Graphics ("How To Create Your Own Texture Resources in Photoshop & Illustrator").

This begins in Photoshop with a photo of a rock surface, where I applied equalization, leveling, and desaturation to get a simplified black and white image. Then I moved it into illustrator and vectorized it with "Image Trace", so I could subtract it from this circle. With a little more work, it could start to look like a palantir.