piedrita
pebble
piedra
stone
+
-ita
diminutive suffix
A piedrita is a pebble, which can be thought of as a small piedra0 (stone0). The -ita1 suffix makes it diminutive1, indicating its small size.
noun
- pebbleA small stone or pebbleEl niño recogió una piedrita lisa del suelo y la lanzó al agua. // The child picked up a smooth pebble from the ground and threw it into the water.