How to Age Stone
If you like the character old, weathered stone brings to a home, you don't need to find stone that is centuries old. You can replicate the effects of many years by following the guide below. Stone masonry is a centuries-old craft that used stones to create long-standing, solid structures. Pyramids and cathedrals are made from stone. Stone is also used for banks, houses, monuments, foundations, walls, walkways, and driveways.
Step 1 - Age Stone with Acid
Stone will take on a weathered look after years of not being protected from acid rain. You can get the same effect by applying lemon juice, vinegar, sour milk, or anything acidic to your new stone. The acid creates gaps and pits in the stone where microbes take hold, aging the stone. Apply acid when the stone is dry.
Step 2 - Create the Tarnished Color of Old Stone
The patina that old stone eventually acquires comes from chemical reactions along with bacteria found on the stone. Any organic matter that works its way into pits and cracks on the stone's surface will give new stone a tarnished look. Manure and compost are two good organic materials to use to age stone.
Step 3 - Use Nutrients to Age Stone
Moss and lichen usually grow on old stone. Your new stone can appear old by promoting plant growth on it. Nutrients such as nitrogen and phosphorous are needed for plants to grow. Using garden fertilizer or manure will help establish the plants.
Step 4 - Use Mixture to Age Stone
Mix together a combination of topsoil, manure, compost, plant fertilizer, and water. Coat the new stone with the mixture and leave it.
Step 5 - Wet and Dry to Age Stone
Stone ages as it is constantly bombarded with wet and dry conditions. Speed up this process by watering the stone when the weather is dry, allow it to dry thoroughly before repeating the process.
Step 6 - Use Sun and Shade to Age Stone
Shaded stone allows algae to grow, which decomposes to create acids facilitating the aging of the stone. Stone in the sun can heat up causing thermal expansion which makes the stone flake on the surface.
By following these steps you will give your stone a weathered, old look.