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 Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased.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. On July 1, 2011, Blackboard agreed to a $1.64 billion buyout by an investor group led by Providence Equity Partners, completed on October 4, 2011. Following the sale, Providence Equity Partners merged Edline, its K-12 learning system, with Blackboard. Edline was later renamed Blackboard Engage. According to a TechCrunch article from 2012, despite its success, Blackboard had become "one of the most disliked — even detested — companies in education." In December 2011, "Fast Company" reported that 93% of respondents to the Amplicate customer opinion survey "hate" the company. In September 2017, Blackboard announced its expansion to the Indian Educational