Move a red gem onto it and it counts down from 3

For Mystery Match level 118, I think the game instructions were a little misleading. It says to drop the symbols (there is only one needed to win the level). But what you really have to do is spear the black jewels with sideways flashers, then when they are all gone, the symbol will drop, and voila, you have won. When I followed the instructions given earlier by Antedon Bifida, they eventually worked, thank you!