The Quartz Corp.

The Quartz Corp is a leading producer of high-purity, low-iron feldspar in North America.

Founded through a joint venture between Norwegian Crystallites and Imerys Minerals, The Quartz Corp is a global company with offices and product stores in Europe, North America and Asia to supply the best possible service to its customers around the world. The Quartz Corp works in partnership with its customers to provide new and innovative solutions.

Why Minspar® for Coatings? — Introduction to Feldspar

Feldspar is a naturally occurring mineral with properties that make it an exceptional filler for use in paint and coating applications. Milled feldspars are composed of angular blocky particles that account for easy dispersion, low vehicle demand, and the ability to achieve high loadings. The minerals’ shape and size distribution allows use at high loadings while providing excellent film integrity. The high GE Brightness, combined with the 1.53 Index of refraction, renders the minerals almost invisible in most polymer film systems; ideal for clear finishes and deep base decorative coatings. Thermal stability is excellent, allowing use in high temperature environments, while the very low available iron content provides superior deterioration resistance at elevated temperature and during weathering, making the minerals ideal for exterior use.

Because of its unique combination of surface chemistry and particle shape, Minspar® can be universally applied in solvent, water-based, high solids, and powder coating formulations. Finer Minspar® grades are ideally suited for satin to semi-gloss gloss coatings while coarser grades are more appropriate for gloss control in the flat to satin range. Minspar® is white and exhibits a slight blue undertone which will not yellow on exterior exposure. Its high Mohs hardness and nodular particle shape combine to provide excellent abrasion resistance and wear properties. Minspar® wets easily and readily with minimal dispersants. It also acts as a grinding aid in obtaining efficient high intensity dispersions of titanium dioxide and other prime pigments. Minspar® has an alkaline pH which will prolong the storage stability of acrylic latex paints or enhance the through-cure rate of elastomeric compositions. It will also help slow the corrosion process in metal primers and coatings.

Minspar® is not hydroscopic so it will not retain surface moisture essential for dirt accumulation and the growth of bacteria and mildew. Minspar®’s unique iron reduction process during manufacture helps protect resin systems from direct sunlight UV exposure for longer service life and improved binder stability. Minspar® produces very durable dry film properties for excellent scrub, abrasion and burnish resistance.

In clear films, Minspar® provides matting in most resin types while maintaining its transparency. The refractive index is almost identical to most of the commonly used clear binders such as polyurethanes, epoxies, acrylics, etc. Virtually transparent in ultraviolet light, Minspar® does not absorb or reflect radiation.

The Quartz Corp offers our Minspar® line; feldspar that is milled to specific particle size distributions, customized for specialized coating applications. Advantages of using Minspar® in coatings applications:

  • Chemically Inert
  • Abrasion and burnish resistance
  • Color consistency
  • Excellent Tint Retention
  • Ease of dispersion
  • Resistance to fading, chalking, cracking and loss of gloss
  • Chemical resistance
  • Formulation flexibility
  • Exterior durability
  • Improved binder stability
  • Non-hydroscopic providing stain and mildew resistance
  • Low iron eliminates iron staining and improves binder stability


MINSPAR® 10 3.2μm | Median particle size | 93.5 GE BrightnessCoatings Industry
A fine grind feldspar for use in satin to semi-gloss, solvent and water based formulations used for interior or exterior applications. Minspar® 10 has a very clean top-size that makes this grade an excellent choice for thin film industrial and powder coatings applications along with architectural coatings. The clean color and low Index of refraction make this potentially useful in a variety of clear coatings.
MINSPAR® 7 4.8μm | Median particle size | 92.2 GE BrightnessA medium grind feldspar for use in eggshell to satin solvent and water based formulations used for interior or exterior applications. Although a medium sized product, Minspar® 7 has a very clean top-size resulting in 6+ Hegman grind coatings. It is an excellent choice for exterior architectural primers, paints and stains, as well as, interior finishes where abrasion resistance is needed. It is also useful in industrial applications where chemical resistance is needed.
MINSPAR® 4 8.0μm | Median particle size | 91.4 GE Brightness
A medium grind feldspar for use in low sheen solvent and water based applications. The combination of median particle size and a very low 325 mesh residue make this a premium choice for formulations that require flattening efficiency without roughness. Minspar® 4 is widely used in traffic coatings and epoxy flooring for its exterior durability, low Oil Absorption, and clean color and can find use in deep base coatings and clear finishes. This is a workhorse for many coating applications.
MINSPAR® 3 12.0μm | Median particle size | 89.5 GE BrightnessA coarse particle feldspar for use in flat solvent and water based applications that is easily dispersed. It is a highly effective product for sheen reduction in flat formulations where durability, texture, and abrasion resistance are needed in thicker film applications.