Polishing Stone Surfaces-What Really Happens

 By Frederick M. Hueston, Stoneforensics.com

The following is an excerpt from my revised Stone Refinishing Bible soon to be published

For those of you who are interested in what really happens during the polishing process the following is a brief explanation:

The polishing process has been studied in depth by several researchers.  A scientist by the name of Beilby studied polishing in 1921 and discovered that a stone surface before it is polished contains rough, viable irregularities. Once the surface is polished, these irregularities become invisible.  Mr. Bielby postulated that what happens is that the top layer becomes glassy, losing its crystalline properties and has flowed over the surface filling in these irregularities.  In other words, the polishing powder tears off the surface of the calcium carbonate atoms and for an instant melts as is smoothed over by surface tension.  This surface layer that is formed is called the “Beilby Layer”.

It was also discovered that the relative melting point of the polishing powder and the stone influenced this flow.  If the powder has a higher melting point than the stone, it will produce a polish. If the powder has a lower melting point than the stone, it will not polish.

Are we confused yet?  If your interested in the complete study , it can be found in the Royal Society of London, Proceedings, Series A, Vol. 160 (1937).  The papers title is: Physical Properties of Surfaces IV-Polishing, Surface Flow and the Formation of the Beilby Layer by F.P. Bowden and T.P. Hughes.

Since Beilby’s initial study in 1921, many other researchers have further investigated the polishing process and the Beilby Layer. It has been found that the formation of the Beilby Layer is not limited to just stone surfaces but can also occur on metal, glass, and other materials.

The Beilby Layer is believed to play an important role in the polishing process by effectively creating a new surface on the material being polished. This new surface is smoother and more uniform than the original surface, resulting in an improved appearance and reduced friction.

The formation of the Beilby Layer is influenced by several factors, including the properties of the material being polished, the type and concentration of polishing powder, the pressure and speed of the polishing process, and the temperature and humidity of the environment.

In recent years, advances in technology have led to the development of new polishing techniques and materials. These innovations have enabled the creation of even smoother and more uniform surfaces, opening up new possibilities in the stone restoration and fabrication industry.

Overall, the study of the polishing process and the Beilby Layer has led to a greater understanding of the fundamental principles underlying the creation of smooth and uniform surfaces. This knowledge has enabled the development of new materials and technologies that have revolutionized many industries and improved the quality of life for people around the world.