A rare and concerning incident has been reported in the chess world. A Russian chess player, Amina Abakarova, is accused of allegedly poisoning her opponent, Umayganat Osmanova, with liquid mercury during a tournament in Dagestan. The incident occurred on August 2 when Osmanova fell ill after seeing tiny gray or silver beads rolling out from beneath the chess board. Symptoms are consistent with exposure to elemental mercury.

Source: https://www.wired.com/story/russian-chess-player-poison-board-mercury/