The Marble Rescue Cheat Sheet: Distinguishing Etches from Stains
How to Identify & Fix Stains, Etches, and Dull Spots.
Etch vs stain determination
Marble damage looks similar at a glance, but etches and stains require opposite treatments. This protocol isolates the physics first so you do not apply the wrong remedy.
Use the flashlight test to classify the damage, then follow the scenario that matches your diagnosis.
Asset card
Baseline material data before any intervention.
The forbidden list
These actions permanently damage marble finishes.
Never use vinegar or lemon
The most common reason for damaged marble is not red wine, it is the wrong cleaning advice. There is a pervasive myth that Vinegar and Lemon are "natural, safe cleaners." On granite, they are fine. On Marble, Limestone, and Travertine, they cause immediate damage.
Never use all-purpose cleaners
Most contain citric acid as a chelating agent, which causes dull spots.
Never use abrasive scrubbers
Green scouring pads scratch the polish and leave permanent haze.
The diagnostic: the flashlight test
Before applying any product, identify the physics of the damage.
- Turn off overhead lights.
- Hold a flashlight at a low angle (raking light) across the surface.
- Look at the reflection of the bulb on the stone.
If the reflection disappears or blurs
This is an ETCH. It is physical damage to the surface polish caused by acid. It feels rough to the touch.
If the reflection remains clear but dark
This is a STAIN. It is color absorbed into the pores. It feels smooth to the touch.
The step-by-step protocol
Select the scenario that matches your diagnosis.
Scenario A: Treating a stain (absorbed color)
- Identify the source: Oil (salad dressing) or organic (wine/coffee).
- Apply a poultice: Mix baking soda with water (for organic) or acetone (for oil) to form a thick paste.
- Cover and wait: Apply paste 1/4 inch thick. Cover with plastic wrap and tape down edges. Poke holes for airflow. Leave for 24-48 hours.
- Remove: Remove plastic. Let paste dry completely. Chip off with a plastic spatula.
Scenario B: Treating an etch (surface burn)
- Assess severity: If you can feel a deep depression with your fingernail, call a professional stone restorer.
- Buffing (light etches only): Apply a marble polishing powder (Tin Oxide) to the spot.
- Friction polish: Use a damp white pad and buff in circular motions until the gloss level matches the surrounding stone.
- Neutralize: Rinse thoroughly with water to remove residue.
The maintenance schedule
Reseal marble countertops every 6-12 months.
Water test: Pour water on the surface. If it darkens the stone within 5 minutes, the seal is compromised. Reseal immediately.