Simplify the following text for a Grade 10 native English-speaking person.
Original: If the resulting pieces of ejecta are small enough , the material is called volcanic ash , defined as such particles less than 2 mm in diameter , sand-sized or smaller .
Simplified: If the pieces of ejecta are small , the material is called volcanic ash , defined as such particles less than 2 mm in diameter , sand-sized or smaller .