NTC

The National Training Center for Stone & Masonry Trades

Stain Removal Guide

YELLOWING

Type:

General yellowing across the surface of most stones, especially white marbles

Problem:

There are many causes for yellowing of stone: UV light can cause yellowing over time; Iron, contained naturally in stone, can oxidize and cause yellowing; Inexpensive coatings can cause yellowing; Mastic used to set stone can yellow.

Solution:

1. If the yellowing is caused by iron contained naturally in the stone, or the stone is aging-forget it, you will never get the yellowing out.

2. If the yellowing is caused by waxes or coating, strip them off according to stripping directions (see Waxes).

Yellowing of white marble, particularly the Carra types, is very common and cannot be reversed at this time.