Calcium sulfate an unusual property: when mixed with water at normal (ambient) temperatures, it quickly reverts chemically to the preferred dihydrate form, while physically "setting" to form a rigid and relatively strong gypsum crystal lattice: This reaction is exothermic and is responsible for the ease with which gypsum can be cast into various shapes including sheets (for drywall), sticks (for blackboard chalk), and molds (to immobilize broken bones, or for metal casting). Mixed with polymers, it has been used as a bone repair cement. Small amounts of calcined gypsum are added to earth to create strong structures directly from cast earth, an
Beyond the Blackboard for Emily VanCamp and Treat Williams since Everwood. The film aired on April 24, 2011 on CBS; it was the last Hallmark Hall of Fame film broadcast on that network, which cancelled the series due to low ratings. Beyond the Blackboard Beyond the Blackboard is a Hallmark Hall of Fame made-for-television drama film starring Emily VanCamp and Treat Williams. It is based on the memoir by Stacey Bess titled "Nobody Don't Love Nobody". The story takes place in 1987 and follows a young teacher and mother of two who, fresh from college, ends up teaching homeless children at a school