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 Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased.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 Inc. to the non-profit IMS Global Learning Consortium developing a prototype for online learning and thinking through online learning standardization. Chasen and Pittinsky started Blackboard after leaving KPMG Consulting where they both had worked as part of the company's higher education practice. In 1998, after Cane met Chasen at a conference on adaptive learning, Gilfus and Cane decided to merge CourseInfo LLC. with Chasen and Pittinky's Blackboard LLC. company in order to raise money and scale the business. The combined company became a corporation known as Blackboard Inc. They renamed the CourseInfo platform built by the Cornell team to Blackboard's CourseInfo;