Below you can find the Small parasitic worms & grains of sand are among the irritants which help these gems form in a shell Jeopardy Words Answer. The answer to Small parasitic worms & grains of sand are among the irritants which help these gems form in a shell has 6 letters. This clue belongs to the Gems category and is part of Jeopardy Word Level 100. If you scroll near the bottom you will find other clues and answers part of level 100