Here you can post elements already in tpt like an element suggestion and give uses, then others can argue for/against. Which elements will stand the test? Some controversial ones to start off with: BTRY, DUST, BOMB and STK2
DUST: Very light dust, flammable. Uses, to make guns, to spread fire, and to make landscapes. BTRY: Battery, generates electricity. Could be used as a more efficiently sized battery. BOMB: Destroys everything except diamond. Uses: Blowing stuff up! >:-) STK2: Second stickman. Could be used for multiplayer stickman games.