This shadow or halo is a sign of moisture in the granite. When the stone gets wet, it turns dark; the granite then dries from the center out, leaving a moisture shadow which has the appearance of a stain. To eliminate this shadow, the granite will have to be dried completely, followed by the application of a good silicone impregnator.
TIP To speed the drying you can place several fans on the granite. Be sure it has dried throughly before applying the sealer.
Article ID: 617
Created: January 21, 2022
Last Updated: January 21, 2022
Author: Pam Freitag
Online URL: https://sr-manual.com/kb/article/when-it-rains-i-notice-a-dark-stain-running-around-the-perimeter-of-each-granite-tile-on-my-back-porch-this-outline-doesn-t-seem-to-ever-go-away-what-s-causing-this-and-can-it-be-cured-617.html