Q.We recently had a light grey Matrix Granite installed in our kitchen. The installer can't figure out how to seal it given its porosity/permeability. The counter still stains with any oily substance (after 3 coats of sealer). Every additional coat of sealer darkens the stone and reduces its iridescence. Do you know of any product will seal this stone and leave it a light grey color that the installer promised?

A. I dont know much about matrix. I assume it is the honed

finish from italy. It appears to be very porous as you stated.

Once you use a specific type of sealer rule of thumb is to stick with same one. Some types of stones can be very porous so you may need more coats. Generally impregnating sealers wont make your stone any darker.

Color enhancing sealers will, so find out what your installer is using. We always tell folks to test their stone selections(prior to purchase) using the lemon test to see how porous it is and if the stone contains calcites. 

We also like to tell people to test before they apply anything to the stone.

Sorry we cant help much here except to tell you to finish the sealing.

Good luck

Stu Rosen