One family's stone took fourteen months and three revisions to get right, mostly because nobody explained the order things happen in. What follows is the order, and the questions worth asking at each step.
The most useful hour a monument buyer can spend is not in a showroom. It is walking the older sections of the cemetery where the stone will stand, reading the dates on markers set in the 1890s, the 1930s and the 1970s, and noticing which ones can still be read from the path and which ones require kneeling and a raking light. The same weather has fallen on all of them. What separates a legible stone from a blank one is almost entirely the material and, second to that, the finish the letters were cut into.
What freeze and thaw actually does to each material
Water gets into a stone, freezes, expands roughly nine percent, and pushes. Granite resists this because its grain structure is tight and its porosity low, so the water that does enter sits in a small volume and does little work; a granite die set in Pennsylvania or Minnesota in 1920 will usually show the same crisp arris on its edges today. Marble is a recrystallized limestone, more open, and it takes water in freely. Bronze does not absorb water at all, which removes freeze damage from the list of things to worry about and replaces it with a different set involving fasteners, the base beneath, and the film on the surface.
The pattern to look for on marble is sugaring, a granular loosening of the surface that feels like fine sand under the thumb and comes off on a glove. Sugaring is not dirt, and it does not stop. Each cycle takes a little more, and lettering that was cut a quarter inch deep in 1890 may be an eighth deep now with rounded shoulders that no longer catch shadow. The Environmental Protection Agency is responsible for tracking acid deposition, which acts on calcite stone by dissolving it slowly and is the second half of why so much churchyard marble has gone quiet.
Which finishes hold lettering and which do not
Finish matters more than most buyers are told. On granite, a polished face gives lettering the highest contrast available, because the sandblasted letter reads matte gray against a mirror-dark ground and stays that way for decades with no upkeep. A steeled or honed face is a middle option, less reflective and slightly more forgiving of hard water spotting, but the contrast between letter and field is narrower from the start and narrows further as the field dulls. A rock-pitched or natural face is handsome and reads poorly; letters cut into it depend on depth alone, and depth is the thing weather takes.
Compare that with marble, where nothing is polished in the cemetery sense and contrast comes only from the shadow inside the cut. That is a fragile arrangement. Once the shoulders round over, the shadow flattens and the inscription becomes a texture rather than words. Bronze avoids the problem entirely by making the letters raised rather than recessed, so legibility survives even when the plate has darkened, because the high points wear bright and the recessed background stays dark. It is the one material where age can improve contrast rather than erase it.
Bronze on a granite base after the maintenance stops
A bronze plaque is typically cast, given a chemical patina and a protective coating, then mounted on a granite base with threaded studs set in anchor cement. Cemeteries that maintain bronze wash and wax it periodically, which keeps the coating intact and the patina even. When that stops, and eventually it usually does, the coating fails unevenly and the plate develops a natural verdigris, green in humid regions and a darker brown-black where the air is drier. This is stable. Bronze corrodes to a product that protects the metal underneath rather than flaking away like rust, so an uncleaned marker from the 1950s is generally sound metal wearing a rough coat.
The genuine failure point is the mounting. Water that collects in the seam between plate and granite, freezes, and lifts a corner will do more damage in ten winters than the air will do in fifty years. So a careful reader checks the seam, asks whether the base is sloped or dead flat, asks whether weep provision exists, and asks what the studs are made of, since a bronze plate on steel studs is a two-metal joint that will eventually complain.
What to check before you sign
Ask which quarry and which color, since granite darkness varies and a light gray takes lettering less boldly than a black. Ask the finish on every surface, not just the front. Ask the letter depth in fractions of an inch. Then go back to the old section and find something that has already answered your question.