Nothing can compare with granite.
There’s so much about granite that just seems right. It is nearly as old as the world itself, and indeed, granite is the material that forms the basic structure of the surface planet upon which we live. It is an inexhaustible resource, continually being created as Earth cools. It is hard, heavy, and durable. It has an infinite variety of structure and colour. It is ageless and beautiful.
Not all granite is suitable for monument crafting. Monument grade granite is very dense with crystals of uniform structure and composition. There can be no fault lines even if practically invisible. Fault lines are actually ‘planes’ of weakened molecular bonding due to mechanical stress or shock.
Also, there can be no trace minerals that will dissolve or change their characteristics due to weathering. For example,traces of iron could rust and cause minor staining. Other undesirable trace minerals might not polish well, or weather poorly, leaving pit marks in the polished surfaces.
Granite is also checked for its imperviousness to water. If it absorbs and retains water, it could be subject to staining by encouraging the growth of lichens or mosses, and in colder climates suffer surface mechanical damage from freeze-thaw cycles.
Of course, visual appeal is a consideration. Granite with a blotchy or streaky texture (sometimes generalized as “rainbow” granite) might present a nice appearance in construction or large monuments, but may not be attractive for smaller monuments. It can also make lettering somewhat more difficult to read. However, sometimes an isolated irregularity within an otherwise uniform texture adds a touch of uniqueness for smaller monuments; what one person might consider a ‘blemish’ others see as a beauty mark.
The effect of polishing the granite is also an important consideration, especially for engraving. Darker, tightly grained granite tends to provide more contrast between a polished surface and the engraved areas. Other granite, especially the light grey colours, may require special engraving methods or treatment of engraved work in order for it to be readily visible. Some granite won’t polish well at all but is still an excellent candidate for monuments, often favoured for bases and accents to the more colourful engraved granites, and as structural material for mausoleums and large monuments.