Does Quartz Countertops Contain Silica?

What is Silica?

Silica, chemically known as silicon dioxide (SiO2), is a colorless or white crystal compound. It is most commonly found as quartz and sand. Silica is present in most minerals on Earth and makes up 12% of the Earth’s crust.

Some key facts about silica:

  • Abundant mineral made of silicon and oxygen atoms.
  • Exists in a crystalline form as quartz.
  • Makes up over 95% of silicon-based rocks and sands.
  • Used to produce glass, ceramics, concrete, fiberglass, etc.
  • Essential nutrient for various organisms.
  • Can cause health issues when inhaled at high levels.

Silica in Quartz Countertops

Quartz crystals are comprised of silicon dioxide molecules arranged in a continuous framework. During the manufacturing of quartz surfaces, quartz crystals are combined with resins, pigments, and other compounds.

The typical composition of quartz countertops is:

  • 90-94% crushed quartz.
  • 6-10% polymer resins.
  • Pigments for color.

So the major component of quartz countertops is silica-rich quartz crystals. The resins bind the quartz particles together to form a durable, non-porous slab.

Why Silica is Added to Quartz Countertops

There are a few key reasons why silica is a vital ingredient in high-quality quartz countertops:

  • Hardness: Silica in the form of quartz rates 7 on the Mohs hardness scale, making it suitable for countertops.
  • Heat resistance: The high melting point of silica allows quartz countertops to withstand heat up to 300°F.
  • Non-porous: The dense silica structure prevents stains from being absorbed.
  • Abrasion resistance: Silica provides excellent durability and abrasion resistance.
  • Chemical resistance: Quartz countertops resist damage from acids, alkalis, and solvents.
  • Color and shine: Silica particles reflect light, allowing quartz to be colored and polished.

Without abundant silica, quartz would lack the durability, strength, and visual appeal required for countertops. Silica makes up over 90% of quartz slabs to provide hardness, weather resistance, and stability.

Is Silica in Countertops Safe?

Silica is an essential and safe mineral when used in countertops. Here are some facts about silica safety:

  • Quartz countertops are chemically inert and do not react with food or household items.
  • Unlike natural stone, quartz does not release harmful radon gas.
  • Silica dust is only a hazard if dry quartz is cut without proper ventilation.
  • Installers must use wet cutting and N95 masks to limit silica dust exposure when fabricating.
  • Properly finished quartz countertops do not release silica dust and are completely safe for homes.

So while breathing crystalline silica dust is hazardous, once quartz is processed into countertops it is completely safe for use in kitchens and bathrooms. With reasonable precautions taken during fabrication, quartz countertops containing silica are non-toxic for consumers.

Frequently Asked Questions

Does all quartz contain silica?

Yes, all natural and engineered quartz contains silica as silicon dioxide is the chemical name for quartz crystals. Silica levels over 90% are typical in quartz slabs.

What’s the difference between silica and silicon?

Silicon is a natural semi-metallic chemical element, while silica is a compound made from silicon and oxygen atoms. Quartz is made of silica, not pure silicon.

Is quartz dangerous due to silica?

Quartz surfaces contain silica but are not dangerous, as the silica dust is contained within the slab and bound with resin. Only cutting dry quartz without protection can produce harmful silica dust.

Does silica get released from countertops?

Finished quartz countertops do not release silica dust. The quartz crystals and silica are completely sealed by polymer resins. Normal use of quartz does not expose anyone to silica.

How are quartz workers protected from silica?

Quartz fabricators use water and vacuum cutting tools to limit exposure to silica dust. They also wear respirators and safety equipment while cutting and grinding quartz.


Silicon dioxide, better known as silica, is the key component of natural quartz crystals. By crushing quartz into fine particles and combining it with resin, durable and safe quartz countertops are created. Although silica dust presents a hazard, finished quartz counters are entirely non-toxic. With reasonable safety measures, quartz countertops with silica can safely be installed and enjoyed in kitchens and bathrooms.