2 What would cause the inscription on a marble gravestone to become harder and harder to read over time?

EROSION. Not erosion . The answer it chemical weathering............;-)hismejohn

Erosion not Erosion the best answer it "Chemical Weathering"..............:-)hismejohn

Marble is a durable stone with small porosity which is why it is often used for gravestones and memorials as well as architecture. Deterioration comes from simply from weathering (rain, snow, wind)...

The most important contributor to the erosion of marble gravemarkers is acid rain. Normal rain erodes marble also, but at a much slower rate than acid rain.

No.