Bluestone is an ingredient encountered in old-time recipes for gambler’s lucky hands and for floor wash used to purify the home. Also known as blue vitriol or blue copperas, bluestone is copper sulphate, a naturally occurring substance that is a highly toxic pesticide, and NOT SAFE to handle. Root doctors and spiritualists who want to work with the blue colour of copperas while avoiding its toxic side-effects use crystalline LAUNDRY BLUEING SQUARES (RECKITT’S CROWN BLUE) instead. These old-fashioned blueing squares, made in France, are completely safe for laundry and bathing. Spiritualists are known to place out pans of protective "blue water" to keep a residence clear of evil spirits. We do not make any claims for BLUEING SQUARES, and sell as a Curio only.