Blackboard ‘chalk’ are produced especially for use with blackboards in white and also in various colours. White chalk sticks are made mainly from calcium carbonate derived from mineral chalk rock or limestone, while colored or pastel chalks are made from calcium sulfate in its dihydrate form, CaSO·2HO, derived from gypsum. Chalk sticks containing calcium carbonate typically contain 40–60% of CaCO (calcite). As compared to whiteboards, blackboards still have a variety of advantages: On the other hand, chalk produces dust, the amount depending on the quality of chalk used. Some people find this uncomfortable or may be allergic to it, and according
That's What Little Girls Are Made Of That's What Little Girls Are Made Of "That's What Little Girls Are Made Of" is the debut mainstream single from Raven-Symoné featuring rapper Missy Elliott (credited as her full name "Melissa Elliott"), taken from her debut studio album, "Here's to New Dreams". This is Symoné's highest chart appearance to date. The song was written and produced by Missy Elliott, who performs a verse of scat singing and Jamaican-style toasting, but the music video featured a thinner light-skinned actress lip-syncing her part. On "Behind the Music" Elliott reveals that she was not informed of the video shoot and later told she