Things You'll Need
White paper towels
Nonsudsing household ammonia, or laundry or dish detergent
Baking soda or natural-stone poultice
Rubber or plastic spatula
Garbage bag or plastic sheeting
Limestone consists of marine bone and shell fragments, compressed to form a solid, yet porous, stone. Limestone comes in a variety of colors, ranging from grays to tans to blues. Manufacturers cut and sometimes polish limestone for use on patios, floors, walls or counters in and around a home; it offers a natural, elegant look. However, grease soaks into the limestone and spreads to form a stain that detracts from the visual appeal, so it requires removal.
Lay white paper towels over the grease to remove it from the limestone's surface.
Pour nonsudsing household ammonia or a laundry or dish detergent over the grease stain. Wet a white rag or natural-bristle scrub brush with water. Scrub the grease stain in a circular motion, starting at the edge of the stain and moving toward the center.
Blot the ammonia or detergent with a white rag. Scrub the stain again with the rag or brush and then blot it with a clean rag. Continue to blot the limestone with a wet rag until no cleaner residue remains.
Pour acetone over the grease stain if the stain is still visible.
Lay a 1/4- to 1/2-inch stack of white paper towels over the stain and place bricks, rocks or other heavy object on top of the paper towels. Leave it overnight to draw the grease out of the limestone into the paper towels.
Remove the paper towels and wash the area with dish or laundry detergent and a rag or natural-bristle brush.
If the grease stain still remains on the limestone, put baking soda into a bowl, add water and stir to form a toothpaste-like consistency. You can also use a commercially available poultice made for natural stone.
Spread the baking soda paste or commercial poultice over the grease stain with a rubber or plastic spatula. Place a plastic garbage bag or plastic sheeting over the poultice.
Place rocks or bricks around the edges of the plastic bag or sheeting to keep it in place. Avoid using tape to hold the edges because tape may leave adhesive residue on the limestone.
Leave the plastic-covered poultice on the limestone for 24 hours. Remove the plastic and gently scrape off the paste with a rubber or plastic spatula. Sweep the remaining baking soda into a dustpan. Place the dried paste into a bucket for disposal.
Flush the area thoroughly with water. Reapply the poultice if any grease stains remain on the limestone.
Consider sealing the limestone with a natural-stone sealer to protect the limestone from spills and stains.
Let the limestone dry completely before determining whether the grease stain remains.
Do not use acid-based cleaners such as vinegar, citrus-based cleaners or muriatic acid to clean limestone.
Do not use stiff brushes or metal scrapers on limestone.
Avoid using dyed rags or paper towels because the dyes can transfer to the limestone.
Keep flames and sparks away from acetone.