Some one just called me the other day to find out ways of removing stains on granite surface and I thought it is a good subject to share my knowledge with folks out there, planning to buy granite for your flooring or counter top projects.
As I quickly found out the stain was kind of rust marks on the surface, which emerged almost a year after installation, my first thought was how to educate the customer to get an understanding of the stone and I started by saying – Granite is composed of minerals like- quartz, feldspar, ferrous, mica, silica in different proportions, and this determines the quality of the stone.
Granite being hard, cutting and polishing demands a lot of manpower and electricity. Water is the only recommended coolant in cutting and polishing. However, as a word of caution, some manufacturers use chemical additives to coolant including kerosene to aid the cutting and polishing to reduce manufacturing cost but compromise on quality.
Use of chemical additives in coolant has devastating effects on the stone in the long run. Mica & Ferrous in the stone reacts to chemicals / kerosene and triggers the oxidation in the stone and the rust will surface over a period of time. This is specifically noticeable in lighter colored granite stones. The chemicals get trapped in the stone no mater how well it is washed in water.
It is important to make sure that the granite you buy is processed only using water as coolant. Also double seal the granite after installation to protect the surface from coming into direct contact with household chemicals that may cause the problem in the long run. Seal the floor once in two years since the household cleaning agents will dissolve the sealer over time.
Certain rust removal chemical agents are available in the market (Iron Out), but it is best tried on a small piece of the stone before trying it out in the prime area of the floor. Always follow manufacturer’s instructions.