General synonyms:
* Stone: This is the most general synonym, encompassing any small rock.
* Gravel: A collective term for small, rounded stones, often found on beaches or in riverbeds.
* Cobble: A larger, rounded stone, typically found in rivers or on beaches.
* Boulder: A large, massive rock.
* Rock: Any solid, naturally occurring mineral aggregate.
Specific synonyms based on context:
* Shard: A small, sharp piece of broken rock, often found in volcanic areas.
* Chip: A small piece of something, especially a rock.
* Grit: Small, hard particles, typically used to describe sand or gravel.
* Clack: A small, rounded stone used for games or as a tool.
The best synonym for "pebble" will depend on the specific context and the nuance you want to convey.