Below you can find the From about 1620 to the mid-1800s firearms used this rock to produce a spark that ignited the gunpowder Jeopardy Words Answer. The answer to From about 1620 to the mid-1800s firearms used this rock to produce a spark that ignited the gunpowder has 5 letters. This clue belongs to the Rocks category and is part of Jeopardy Word Level 125. If you scroll near the bottom you will find other clues and answers part of level 125