Hypertufa spiral, crystal and color

The white speckles is crushed shells

 I poured this last night using 3 pigments; red, mustard and black, using the pure Hypertufa to separate the colors in a experiment to create geologic sediment appearance. I have no idea what this will look like when cured, but, I think the next time I try this I will skip the crushed shell as I think it threatens the already compromised cement's integrity. 
Like anything else, I learned how I want to approach my next project and how the pigmented Hypertufa needs to be poured to try to control the areas to be effected.

This is my mold, duct tape and 3 plastic ties keep the stovepipe  together as well as easy release the next day.

The crystal was a last minute decision, so I made a cavity at the center and will use pure cement to keep it in place, I hope!