Does white quartz turn yellow?

White quartz is a mineral composed primarily of silica and oxygen. It has a hard, glassy appearance and is often found in geometrical formations. While white quartz countertops and tiles are popular choices for home decor, their colour may turn yellowish over time due to various factors.

Exposure to Sunlight

Exposure to excessive sunlight is one of the primary causes of white quartz turning yellow. The UV radiation in sunlight can break down chemical bonds in quartz, resulting in the formation of yellow pigments. Placing white quartz surfaces in direct sunlight through windows can accelerate this process.

Presence of Iron Oxide

Trace amounts of iron oxide present in white quartz can oxidize when exposed to air, causing the formation of yellow stains. The iron oxide reacts with oxygen and moisture to form iron hydroxide, which has a characteristic yellow or brown colour. This is more likely to happen in porous types of quartz with greater surface exposure.

Weathering and Ageing

As white quartz surfaces age, the passage of time results in the accumulation of yellow stains due to weathering and oxidization. Surface abrasions and microfractures increase the exposed surface area, allowing more interactions with oxygen and minerals that can discolour the material. Older quartz surfaces, therefore, tend to develop a yellow patina.

Preventing White Quartz from Turning Yellow

While it may not be possible to prevent white quartz from turning yellow completely, there are some steps you can take to slow down the process:

• Avoid exposing white quartz to direct sunlight as much as possible. Use curtains to limit sun exposure.

• Clean white quartz surfaces regularly to prevent the buildup of stains and grime. Use a mild detergent and soft cloth. Avoid abrasive cleaners.

•Consider applying a sealant or protective coating to the surface of white quartz. Impregnating sealants can shield the material from discolouration. Re-apply the sealant every few years.

• For natural white quartz, limit exposure to heat which can accelerate the oxidization of iron oxide. Use trivets and heat pads under hot objects.

Removing Yellow Stains from White Quartz

If white quartz surfaces have already developed yellow stains, it is possible to remove them and in some cases restore the original colour. Some methods for yellow stain removal include:

• Scrub the yellowed areas with an abrasive paste of baking soda and hydrogen peroxide. Rinse well with water and repeat if necessary.

• Apply a commercial stone bleach or whitening product as per the directions. These products contain oxidizing agents to bleach the yellow stains.

• For persistent stains, it may be necessary to hire professional restoration services. Technicians will use a combination of chemical etchants, abrasives and re-polishing pads to strip away layers from the surface and restore the white colour.