What causes dye to bleed from an agate stone? I came across this review on Amazon. The cold drink was placed on top of the agate stone and the dye bled and left a permanent mark on the table.
Why does this happen? Is it because of the condensation as mentioned by the customer? Can regular warm water also cause the same effect?
I just want to know why dyes work, and what makes them bleed.
Dyeing agate is a common practice- the stone is real, but it's been cosmetically altered. The stone gets soaked in a chemical solution, which is absorbed into the microscopic pores in the stone.  Whatever dye the person who made these coasters used must have been water-soluble.  So, yes, cold water would also cause the pigments to bleed.