Two limestone/or marble tombstones: Two granite/or gneiss tombstones：
Summary： I found two marble/limestone tombstones, one from the 19th century and the other from 2018; and the two granite/gneiss tombstones are from 1966 and 2020 respectively. By observing and touching these four marble tombstones, I noticed that the granite/gneiss tombstones seemed to have deeper carving depths, while the carving marks on the marble/limestone tombstones were relatively shallow. By comparing the older and newer tombstones, I found that the older marble tombstone showed a higher degree of weathering, with noticeable signs of weathering on its base, while the granite tombstone showed almost no signs of weathering. From this, I deduce that it's likely because marble/limestone is relatively softer in texture compared to the hard and durable granite. Therefore, it is more difficult for
marble/limestone to withstand deeper carving marks during the carving process. Additionally, marble is more susceptible to weathering and erosion compared to granite. Due to its higher calcium content, it is more prone to dissolution and abrasion. Therefore, overall, marble tombstones have shallower carving depths and are more susceptible to weathering and damage, while granite tombstones are more durable and resistant to weathering.