* Granite is Igneous: Granite forms from the cooling and solidification of magma deep within the Earth.

* Magma Formation is Continuous: Magma is constantly being generated in the Earth's mantle and rises to the surface.

* Granite Formation is Ongoing: This means that granite is continuously being formed, making it impossible to assign a single age to it.

Instead of a specific age, we talk about the age of individual granite formations:

* Radiometric Dating: Scientists use radiometric dating to determine the age of specific granite formations. They analyze the radioactive decay of elements within the rock to calculate its age.

* Age Varies: The age of granite formations can vary widely, from millions to billions of years old.

Therefore, rather than asking "How old is granite rock?", it's more accurate to ask "How old is this specific granite formation?"