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 Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased.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
Blackboard Learn October 2017, Blackboard partnered with OpenEd to integrate OER with Learning Management Systems. Blackboard Learn provides users with a platform for communication and sharing content. Blackboard Inc has had several legal issues, including faulty patent rights claims. In addition, a number of educational institutions, teachers, and students have expressed concerns about the reliability of Blackboard. McMaster University in Hamilton, Ontario, Canada, has replaced their Blackboard system after multiple problems during one year of use. Citing numerous glitches and high costs, many universities are turning to the cheaper, open source alternative Moodle, including Montana State University, Vassar College, California State University,