Chalk It is formed in the sea by sub-microscopic plankton, which fall to the sea floor and are then consolidated and compressed during diagenesis into chalk rock. Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased. Blackboard chalk manufacture now may utilize mineral chalk, other mineral sources of calcium carbonate, or the mineral gypsum (calcium sulfate). While gypsum-based blackboard chalk is the lowest cost to
Chalk talk Chalk talk A chalk talk is a monologue presentation done while the speaker draws. It is usually done with chalk, hard crayon, or pastel, or with dry-erase markers on a whiteboard. The chalk talk method of teaching focuses on the blackboard and the lecturer's voice and also the activities – to be precise, the physical activities. This method can be preferred for presenting lectures and talks. Because of an article in the "Deseret News" published on September 17, 1895 the roots of "chalk talks" can be traced to the Methodist church - and a singular individual - Mr. Frank Beard