Cleaners That Dull a Quartz Finish
Damage by Accumulation
Nothing in a cleaning cupboard will ruin a quartz top in one use. The problem is that a daily product used for two years is two years of exposure, and the change is gradual enough that nobody notices until a patch is compared with an area that never gets cleaned, such as under a fruit bowl.
Abrasives Are the Fastest Route
Cream cleaners and scouring powders work by being harder than what they are removing. On a polished surface they leave a dense field of fine scratches which read as haze rather than as scratches. Scouring pads do the same. The polished finish is a surface treatment and it is thinner than people assume.
High pH Products Attack the Binder
Strongly alkaline degreasers, oven cleaners and bleach based sprays soften and gradually break down the polymer holding the mineral together. Occasional use is not a crisis. Routine use of an alkaline spray as the daily wipe down is the most common cause of a top that has lost its sheen in patches.
Solvents and Marker Removal
Isopropyl alcohol is safe for lifting adhesive residue and ink and is the right tool for occasional spot work. Acetone and paint thinners are not, and neither are the aggressive removers sold for grout haze. If something needs a solvent, use the mildest one that works and rinse it off.
What Actually Works
Warm water with a little dish soap, a soft cloth, and a dry cloth afterwards to stop water marks in hard water. For anything stuck on, a plastic scraper rather than an abrasive. For a periodic deep clean, a cleaner specifically labelled for engineered stone, used at the stated dilution.
Restoring a Dulled Surface
Once the finish has gone, quartz does not respond to refinishing the way natural stone does, because the resin does not take a polish in the same manner. Specialist firms can improve it, and the result is usually better rather than new. Prevention here is not a slogan, it is the only reliable option.