Quartz countertops have become incredibly popular in recent years for kitchen and bathroom remodeling projects. But despite their name, quartz countertops are not made entirely of natural quartz mineral. These engineered surfaces typically contain between 93-97% ground quartz combined with resins, polymers, and pigments. Understanding the exact composition of quartz countertops can help homeowners make informed decisions when selecting countertop materials.

What is Quartz?

Quartz is a naturally occurring mineral found abundantly in the earth’s crust. It is composed of silicon and oxygen atoms and has a chemical formula of SiO2. In nature, quartz crystals form in a variety of colors including white, purple, pink, yellow, brown, black, red, and orange. Quartz is known for its high hardness and scratch resistance. It has a ranking of 7 on the Mohs hardness scale, which makes it harder than most other natural minerals.

Some key facts about natural quartz mineral:

Extremely abundant mineral found worldwide
Crystalline structure with six sides
Hardness of 7 on Mohs scale
Naturally found in a variety of colors
Used in many industrial applications

Natural quartz crystals are mined and then processed for use in quartz countertops and other commercial and industrial uses. The high hardness and scratch resistance make it an ideal material for countertops that can withstand heavy daily use.

Composition of Quartz Countertops

Although they are marketed as “quartz countertops,” engineered quartz surfaces contain only a percentage of actual quartz mineral. Exact percentages can vary by brand, but quartz countertops typically contain:

93-97% crushed or ground quartz – This is natural quartz mineral that has been mined and then processed into a fine powder. The ground quartz provides the hardness, durability, and look of natural stone.
3-7% resins and polymers – Polymer resins such as polyester work as binders to hold the quartz powder together. Resins impact the flexibility, strength, and workability of the material.
Pigments for color – Pigments are added to achieve the desired color and pattern for each quartz variety. Manufacturers can create hundreds of color options.

In addition to these main ingredients, some quartz countertop products also contain:

Recycled glass, mirrors or metals
Antibacterial agents
Extra polymers for flexibility
Small amounts of other minerals like aluminum oxide

So in summary, although they contain the word “quartz,” engineered quartz countertops are only 93-97% actual quartz mineral. The remaining small percentage is made up of resins, polymers, and other additives.

Why Use Ground Quartz?

There are a few key reasons why engineered quartz uses high percentages of ground quartz rather than being made completely of polymer or resin:

Hardness and Durability

The quartz mineral provides hardness and scratch resistance to the material. With proper sealing, quartz countertops stand up well to heavy day-to-day use without etching or scratching.

Natural Stone Look

The ground quartz gives quartz countertops the elegant look, feel and texture of natural stone. This sets it apart from solid surface acrylic counters.

Stain Resistance

Quartz is non-porous so it does not easily stain from spills and foods. While sealing is still required, quartz is one of the most stain-resistant countertops available.

Heat Tolerance

Quartz countertops can tolerate brief exposures to heat up to 212°F and are somewhat more heat resistant than natural stone or solid surface counters.

Using ground quartz enables manufacturers to take advantage of the durability, performance and aesthetics of natural quartz in an engineered surface.

How Quartz Countertops Are Made

Understanding how quartz countertops are manufactured gives more insight into why quartz makes up 93-97% of the final product. Here is a basic overview of the manufacturing process:

1. Mining and Crushing Quartz

Natural quartz is mined from the earth, then crushed and processed into a fine quartz powder. Manufacturers carefully control the size and texture of the crushed quartz.

2. Mixing with Resins and Pigments

The ground quartz is combined with polymer resins, pigments and any other additives in precise percentages in a large mixing vessel.

3. Pressing Into Slabs

The mixture is then pressed into molds under vacuum conditions to remove air pockets. Pressure of up to 100 tons is used to compact the material into solid slabs.

4. Curing and Polishing

The quartz slabs cure in a curing chamber then the surface is polished to a smooth, shiny finish. The slabs are later cut to finished countertop dimensions.

5. Installation

The prefabricated quartz countertops are installed by professionals using adhesive and seam techniques to get perfectly tight seams.

The addition of the resin binders and polymers is necessary during manufacturing to hold the ground quartz together in a durable, non-porous surface. But quartz remains the primary component of the engineered surface.

Pros and Cons of High Quartz Content

The high percentage of quartz used in engineered quartz surfaces results in some key advantages:

Pros

Extremely hard and durable surface
Maintains beauty and color without sealing
Resists stains, scratches and heat very well
Non-porous so does not harbor bacteria
Color and pattern consistency between slabs

Cons

Heavy material requires professional installation
Can chip if subjected to sudden impacts
Limited number of colors/patterns compared to natural stone
Resins may yellow over time with sunlight exposure

Using 93-97% quartz creates an ideal balance between the durability of quartz and the flexibility of resin binders. Homeowners get an incredibly low-maintenance, stain-resistant countertop.

How Quartz Content Impacts Performance

Why does the percentage of quartz matter for performance and durability? Here are some key reasons:

More quartz = harder surface – Higher quartz content means a harder, more scratch-resistant countertop.
More quartz = less resin yellowing – Over time, the resin binders in quartz can gradually yellow with sun exposure. Products with higher quartz and less resin will see less discoloration.
More quartz = better stain resistance – Natural quartz is less porous than resin, so higher quartz makes the surface more impervious to stains.
More quartz = better heat resistance – Durability under heat improves slightly with higher mineral content. Burn marks are still possible though.

Within the typical 90-97% range, quartz content has a modest impact on performance. But differences become more noticeable with lower quartz percentages or in cheap quartz products.

Is a 100% Pure Quartz Countertop Possible?

Because resin binders are required in the manufacturing process, counters made of 100% raw quartz are not possible through normal fabrication. The resins are essential to hold the ground quartz particles together into a solid slab and provide flexural strength.

Without any binder, the quartz pieces would simply fall apart and be unusable as a countertop. The polymer resins allow quartz surfaces to be molded into seamless countertops of any shape and size.

There are a few options that come close to 100% quartz:

Quartz tiles – Small quartz tiles require less resin since more seams allow flexibility. Resin content may be slightly lower.
Concrete + quartz – Some DIY options use concrete as the binder instead of resin. This results in a more mottled, rustic look.
Sintered quartz – Quartz powder is oven-fused into pure solid sheets, but this process is challenging and expensive.

For most homeowners, conventional 93-97% quartz countertops offer the best combination of pure quartz performance and easy fabrication into custom countertops. Careful sealing and maintenance is the best way to maximize the benefits of the high quartz content.

FAQs about Quartz Countertop Composition

Here are answers to some common questions homeowners have about the composition of quartz countertops:

What percentage of quartz is in a quartz countertop?

Typical quartz countertops contain 93-97% crushed and ground natural quartz. The remaining 3-7% is polymer resins and pigments.

Can you get 100% quartz countertops?

It is not possible to have a countertop made of 100% solid quartz, since resins are required to hold the material together. But some options like tiles may contain slightly more quartz than typical slabs.

Does more quartz mean a better countertop?

Within the normal range, a higher quartz percentage results in better hardness, durability, and stain resistance. But even 90% quartz surfaces perform extremely well.

Do all quartz countertop brands have the same quartz content?

The exact percentage can vary slightly between brands, but all major brands use over 90% quartz. Lower-cost quartz products may have lower quartz content with more resin filler.

How does quartz content affect resins yellowing over time?

Products with less resin and more quartz mineral will exhibit less yellowing or discoloration from UV exposure over many years. Quality quartz should maintain color well for 10-15 years.

**Can you get quartz countertops in pure white? **

Most bright white quartz varieties will contain small flecks of other minerals and colors. Pure white is difficult to achieve since totally pure quartz is only found in a limited number of natural colors.

Do natural quartz crystals have the same performance as engineered quartz?

No, natural quartz crystals are too porous and inconsistent for counter surfaces. Engineered quartz mimics the look of quartz but has much better durability.

Achieving A Natural Quartz Look

For homeowners who want counters that strongly resemble natural quartz stone, here are some tips:

Choose a white, gray, or beige color rather than bold colors which look more artificial.
Seek quartz varieties with subtle veins, flecks, or crystalline patterns.
Select a matte or lightly textured surface instead of a polished look.
Consider combining quartz with other natural materials like wood or stone accents.
Use quartz for non-conspicuous areas and natural stone for main surfaces.
Opt for quartz tiles instead of a full slab if you want to maximize pure quartz content.

With an expert design eye, quartz counters can take on the aesthetic of a natural material while still providing the best qualities of an engineered surface.

Is a Higher Quartz Percentage Worth it?

For most homeowners, the standard 93-97% quartz content offers an ideal combination of durability, stain resistance, and heat tolerance compared to natural stone or other countertops. Products from reputable quartz brands with rigorous quality control will provide excellent performance for years.

The slightly higher quartz content of one brand versus another is usually not a significant factor. Things like color, pattern, warranty terms, and price are more important considerations for most buyers. Maintenance and care have a greater impact on the counters’ lifespan than small differences in material percentages.

However, those seeking maximum durability may want to verify exact quartz content from the manufacturer. Specialty options like sintered quartz counters with almost 100% quartz are also available for those requiring ultimate performance. For best value, standard quartz delivers exceptional quality for daily use in kitchens and baths.

Conclusion

Understanding that quartz countertops contain over 90% ground quartz mixed with resins gives homeowners realistic expectations about the composition. Although not completely natural stone, the high quartz content quartz delivers the elegant look and durability of solid quartz. When combined with polymers and pigments under extreme pressure, you get an engineered surface that outperforms natural stone. With proper maintenance, quartz counters will remain beautiful for many years of daily use.

What Percent of Quartz Countertops is Quartz? Key Takeaways:

Standard quartz countertops are 93-97% crushed and ground natural quartz mineral.
Remaining 3-7% consists of polymer resins, pigments, and other minor additives.
Quartz provides hardness, durability, and scratch resistance. Resins hold the material together.
Higher quartz content results in greater stain resistance and heat tolerance.
Quartz countertops cannot be made from 100% solid quartz pieces.
For most buyers, a typical 90-97% quartz content offers the ideal combination of performance and value.

What Percent of Quartz Countertops is Quartz?