Before you try anything: always speak to a professional before cleaning, treating or applying any product to your stone. Every slab is different, and the wrong product can cause permanent damage. Contact us or a qualified stone restorer first.
Quick answer
Red wine stains in onyx lift with a hydrogen peroxide poultice: blot the wine immediately, wash the area, then leave the poultice covered for 24 to 48 hours to draw the colour out. Wine is acidic, so on onyx a dull ring may remain after the colour is gone; that is an etch and is fixed by polishing.
First, check what you are dealing with
- Purple, pink or grey-blue mark: a wine stain. Follow the steps below.
- Pale, dull ring where the glass stood: an etch from the wine's acidity.
What you need
- Paper towel
- pH-neutral dish liquid
- Hydrogen peroxide
- Flour, talc or diatomaceous earth
- Plastic wrap and tape
- Plastic scraper
Step by step
Blot fast
Blot up every drop straight away. On onyx, the first few minutes decide how deep the colour goes.
Wash the area
Clean with warm water and a few drops of pH-neutral dish liquid, rinse and dry with a soft cloth so you can see what is left on the onyx.
Test first
Try the mixture on a hidden spot of your onyx (inside a cut-out or under an overhang) and check the finish after it dries.
Mix the poultice
Stir an absorbent powder (plain flour, talc, diatomaceous earth or whiting) into hydrogen peroxide (3% from a pharmacy for fresh stains, or 12% from a hairdressing or pool supplier for older ones) until it has the consistency of peanut butter.
Apply it
Spread it 5 to 6 mm thick over the wine stain, extending about a centimetre past the edge. On onyx, stick to 3% peroxide and check after 24 hours rather than 48.
Cover and wait
Cover with plastic wrap, tape the edges and poke a few small holes so it dries slowly. Leave it 24 to 48 hours until completely dry: the drying is what pulls the stain up into the powder.
Remove and rinse
Lift the dry poultice with a plastic scraper, rinse with clean water and dry the onyx. If the wine stain is lighter but still there, repeat up to three times.
What not to use on onyx
- Vinegar, lemon juice or "natural" citrus cleaners: they etch onyx.
- Scourers, steel wool and abrasive creams on a polished surface.
- Mixing cleaning chemicals, especially bleach with anything else.
- Salt, soda water and white wine "tricks": they do nothing for stone and can spread the stain.
When to call a professional
If colour remains after three rounds, or you are dealing with a large etched area, call a restorer. Onyx needs a restorer who works with it regularly: it is softer and more fragile than marble and easy to over-polish.
Understanding red wine stains on onyx
Architectural onyx is banded calcite. It is less absorbent than limestone, but its translucency means a stain can show from both sides of a backlit piece.
Onyx is calcite and usually highly polished, so a drop of lime or wine leaves a dull etch that catches the light immediately.
Onyx needs a restorer who works with it regularly: it is softer and more fragile than marble and easy to over-polish.
Good to know
On backlit onyx bars, red wine can show as a coloured shadow when the lights are on. Blot immediately and call a restorer rather than using strong peroxide on onyx.
Stop it happening again
Whether yours is honey, white, green and pink banded onyx, often backlit, repairing it fixes today's mark; protecting it stops the next one. Our clear Stone Protection Film sits over the surface, so acids cannot etch it and liquids cannot soak in. Onyx is usually polished, so Gloss film is the natural match and keeps its reflective depth. It is installed across Sydney with a 10-year written warranty.
How we protect onyx · Stain removal guide · Red wine stains on every surface