There appears to be no concrete reasoning as to when or why St. Nick made the landmark decision to hand out lumps of fossil fuel, however, speculation abounds among historians!
Santa’s mode of operation is a soot-filled slide down a chimney to bring gifts to little girls and boys. In the beginning, hundreds of years ago, Santa would leave treats in shoes sitting by the fireplace. For all those little kids with Grinch-like behavior, it was just easier for St. Nick to grab a lump of coal from the fireplace he had just traversed. In time, Santa began placing candy and money in stockings that were hung from the mantel with care. The behaviorally-challenged child will receive a bit of Christmas charcoal in hopes they change their ways by next year.
Santa has also been said to leave bundles of twigs, bags of salt, garlic and onions.