Standard silicone contains silicone oil that can penetrate into porous stone and therefore will show a darker edge next to the seal. This is called edge-of-seal contamination and cannot be removed or reversed. Specially formulated natural stone silicones prevent this and will therefore not lead to edge-of-seal contamination when used on natural stone (e.g. Silirub MA).
For more information and product recommendations visit our natural stone sealing application page.