|MadSci Network: Chemistry|
I have a simpler solution.
Get a dark colored rock with LOTS of cracks and crevices. Then go to the supermarket and get red food coloring(liquid), drip the food coloring onto and in the rock's crevices. LET it dry, reapply and dry once again.
The rock is then ready to "bleed", put a small sponge in your palm soaked with water. pick up the rock and squeeze.
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