Sakura Red stone naturally contains iron salts and calcium compounds in cement that seep through the capillary pipes to the surface when acted upon by water, causing various "diseases." Waterproofing and anti-staining treatments are required. Additionally, polished stone surfaces become slippery when wet, with the coefficient of friction on damp stone surfaces potentially as low as 0.2. Walking on such wet, untreated stone floors is unsafe, and anti-slip treatments are necessary.