From Writing Our Way Home:
A small stone is a very short piece of writing that precisely captures a fully-engaged moment.
There are no strict rules for what makes a piece of writing a small stone, as there are for forms such as haiku. The process of finding small stones is as important as the finished product – searching for them will encourage you to keep your eyes (and ears, nose, mouth, fingers, feelings and mind) open.
Small stones are published at A Handful of Stones.