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 Most people first encounter the word "chalk" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased.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
What Planet Are You From? What Planet Are You From? What Planet Are You From? is a 2000 American science fiction comedy film directed by Mike Nichols and written by Michael Leeson, Garry Shandling, Ed Solomon, and Peter Tolan based on a story by Leeson and Shandling. The film stars an ensemble cast featuring Shandling, Annette Bening, Greg Kinnear, Ben Kingsley, Linda Fiorentino, and John Goodman. A denizen (Garry Shandling) of a faraway planet occupied only by highly evolved males is ordered by his superior, Graydon (Ben Kingsley), to find a female human, impregnate her and bring the baby back to the planet. The visitor