I have left a stone on a grave for a family member. But, for my Grandparents, we leave a fresh take out coffee (paper cup) and a cigarette, not lit. It's something they would like, if they were still here. It's not the only way we remember them. But, its how we remember the small every day things about them. Plus, its much easier to leave a coffee than so many other things. I don't want to litter, or cause extra clean up for the staff who maintain the cemetery.

I did wonder about the tradition of leaving a stone on a grave. I found a post about it, from Joy Neighbors, on her old site.

For thousands of years, people were buried in tombs or directly in the earth where they had fallen. Stones were then rolled in front of a tomb as a way of sealing it from scavengers and keeping evil spirits from escaping out into the world.

For those buried in the ground, rocks and stones were placed on top of the usually shallow grave to keep animals from digging up the body. These stacks of stones were known as cairns. Cairns can be found all over the world and vary in size from a few rocks to man-made hills.

Cairns were built not only as funeral monuments but also for ceremonies and defense. Today they are still constructed to mark trails, as seamarks, as sculpture, and as memorials.

Another reason rocks were left on the grave was based on an Eastern European folklore belief that the dead could haunt their burial place, or return to their family and cause trouble. Stones and rocks were used to prevent the deceased from rising up and escaping the body as a spirit, to torment others.

It is also a Jewish custom to place a stone or pebble on a headstone to indicate that you have visited the grave and to indicate respect for the deceased. Adding a stone was also seen as taking part in the Mitzvah of Matzevah or the ‘setting of stone.’

Today, leaving a stone of remembrance is viewed more as a way of continuing this tradition of commemoration. The more stones found at a grave, the more the deceased has been visited and remembered by others. An example would be the scene in Schindler’s List when the people that Oskar Schindler saved visit his grave and honor him by placing stones upon it.

Symbolically, the stones can indicate many things; that love and remembrance are as strong and as lasting as a rock. That as a stone lasts forever so to does love. Even a belief that the deceased is with God, since the Old Testament refers to God as a rock, as in Psalm 18:2 -- "The Lord is my rock…”

Regardless of how the custom came about, it is still an incredible way to remember and respect those who have passed on. Leaving a stone or pebble is a gesture of appreciation for the strong and lasting impression they have made on your life. Stones left by others show a long-term influence in their lives as well. What a wonderful way to leave a lasting tribute of love and honor at the grave site.

Source: A Grave Interest: Leaving Stones on Graves Joy Neighbors.

Description from the site:

I am a Tombstone Tourist: someone who loves to wander cemeteries. I find it akin to visiting a museum: an opportunity to enjoy rarely seen sculpture, intricate carvings, and amazing architecture, all in a tranquil outdoor setting. This blog is about cemetery culture, art, history, issues of death, and genealogy - subjects of current relevance. I usually find something that intrigues me and makes me want to dig deeper. Care to join me? Read on...