What causes the discoloration of monuments in the cemetery?
Granite is composed of quartz, feldspar, mica and other materials. There are sometimes also traces of ferrous metals in oxide form. When a strata of granite containing ferrous (iron) metals is used for monumental purposes, oxidation occurs and the granite changes color. White granite with such impurities turns brown or yellow. Another frequent cause of discoloration is the use of “top quarry” granite for monuments. When a new area is cleared of top soil for quarrying, the top layers of granite have been saturated with organic and inorganic chemicals contained in the soil immediately above it. These impurities, which have been absorbed by the top layers of granite are called “sap”. They are not apparent in newly manufactured monuments, but exposure to the elements at the cemetery dissolves them and makes them come to the surface. Although the supply of granite is inexhaustible, only about twenty percent is suitable for monumental use.
