GreenStone/ Ecostone is replacing pumice stone 100% while achieving a similar but cleaner look. Pumice stone has been a trademark process for decades on all discharged, washed down looks on denim called "stone wash" but pumice stones dissolve in to sludge after only one use. In contrast, GreenStone can be used extensively for over 1000 washes without creating any sludge residual whatsoever.