In our many years of practice, we have worked on many different natural stone projects and marble restoration is the most common of all. We get questions from “how do I keep the high shine?” to “what’s the cheapest way to do it?” I guess most restoration companies would right away say “crystallization” is the answer. But what is crystallization? Let’s take a look at its pros and cons.
This method also known as vitrification makes use of a chemical and steel wool pads that create friction and heat on the surface of the marble to achieve a high gloss finish. It is the most commonly used maintenance for high traffic areas that demands a consistent shine such as a hotel lobby.
The key chemical used for crystallization process is fluorosilicon. This compound contains enamel wax and acid. It may sound strange to use acid on calcite stone since acids harmful to stone and are the main cause of etching. In this case however, the acid is used to break down the calcium carbonate and allows it to bond with the fluorsilicate creating a new compound known as calcium fluorosilicate. This process will chemically alter the surface of the stone producing a harder finish which later results in spalling and cracking.
While crystallization gives you an immediate shine, it also leads to many long term problems. Here are a few:
1. MONEY. Since crystallization consists of wax, it is subjected to quickly loose its shine which means the process must be repeated. The super high gloss finish quickly fades. The shine is only temporary so the restoration company needs to come back and repeat the process once again.
2. SCRATCHES. The scratches that were present before the crystallization process are still there, the only difference is that now they are shiny. These scratches accumulate dust and dirt throughout the course of the day.
3. DISCOLORATION. Many customers complain about their stone turning a slight orange-red color. The cause of this strange discoloration is that the steel wool pads leave iron behind which eventually rusts within the stone.
4. SPALLING and CRACKING. As mentioned earlier, the crystallization process produces a harder finish and the stone begins to dry, crack and chip away.
5.HEALTH HAZARDS. When using the crystallization method be sure to request your marble contractor the MSDS (material safety data sheet) for the chemical crystallization being used, most often the chemicals cannot be used indoors and can cause skin rashes, eye irritations, and respiratory complications.
Crystallization can be a very good short term solution for a low budget customer so long as they understand the consequences, if the recrystallization process continues the stone will begin to deteriorate and eventually fall apart forcing the costumer to replace their natural floors. In our many years of experience we are witnesses of the damage crystallization can bring within your home or business.
For more information about how crystallization can also be a hazard to your health watch this interview with Dr. Fred Hueston on the topic.