Canadian Fairy Stones (Harricana River)
These are natural concretions made of calcium carbonate and clay. They formed at the bottom of glacial lakes thousands of years ago. As the glaciers melted, mineral-rich water dripped into the clay, hardening it into smooth, rounded shapes.
 
Appearance: These look like smooth, grey river stones that have been fused together. They often resemble small animals, birds, or "mother and child" figures.
Surface: One side is usually flat and smooth, while the other side can be bumpy with intricate patterns left by ancient microorganisms or plant life.
Geology: They are essentially hardened "mud balls" that have been reinforced by calcite. Because they were formed in moving water and clay, no two are ever identical.