Decorative and Protective Stucco With SMI Calcium Carbonates

Stucco is a popular finish for building exteriors, either as a decorative accent on a vinyl- or wood-sided or brick house, or as the overall coating on all walls. It is durable, serviceable protection for all sizes of buildings.

Calcium Carbonates in Stucco
Ground calcium carbonate has many uses in architectural applications, one of the largest being stucco products. Stucco systems range from simple, traditional, natural coatings to complex, multi-layer synthetics. All use a ground mineral such as ground calcium carbonate (GCC), also called ground limestone, ground dolomite (calcium magnesium carbonate), or washed sand.

Traditional, built-up stucco exteriors use a ground limestone or dolomite as the aggregate in the topcoat. Synthetic stuccos involve a four-part application system, where limestone is used in several layers as a functional filler, and in the topcoat as a texture aggregate. The size of calcium carbonate filler chosen can range from 10 mesh to 200 mesh, with the size choice depending on the application.

Specialty Minerals Calcium Carbonates in Stucco
Specialty Minerals Inc. (SMI) manufactures screened, ground, and pulverized limestone and dolomite products used in traditional and synthetic stucco formulations. The SMI plants in Adams, Massachusetts and Lucerne Valley,California, make high purity, high-brightness ground calcium carbonates (GCCs) or limestones for both stucco finish aggregate and filler usage. The Canaan, Connecticut SMI plant makes ground calcium magnesium carbonates or dolomites with excellent color.

The families of Specialty Minerals ground limestones and dolomites for stucco formulations are:

  • Marblewhite® GCC - East – high-brightness 200 mesh ground limestone.  It is available from the SMI plant in Adams, Massachusetts.

  • Marblewhite® GCC - West – high-brightness ground limestones of particle sizes from 10 mesh to 200 mesh.  Manufactured in Lucerne Valley, California.

  • Vical® GCCs – East – 16 to 100  mesh, dedusted limestones with moderate brightness, from Adams. 

  • Vical® GCCs – West – 16 to 100 mesh, dedusted limestones with moderate brightness, from Lucerne Valley.

  • ATF™ GCCs – bright screened limestones, in 10 to 40 mesh grades, manufactured in Adams.

  • DF™ dolomites – bright 10 to 20 mesh ground dolomites, from Canaan.


We are also able to design new products to meet the needs of your particular stucco application. Contact us about your needs.

With all of these products for stucco usage, SMI tightly controls the manufacturing process in order to meet the aggregate gradation specifications and particle-size distributions. Thus the desired final visual effect in the stucco topcoat is consistently achieved.