Trivia: Blackboard Chalk Isn’t Made of Chalk

By Alex in Daily Trivia on Apr 18, 2008 at 1:21 am

Blackboard chalk is made of gypsum, not chalk.

Chalk is a type of limestone composed of the mineral calcite. Blackboard chalk used to be made from natural chalk, but it has since been replaced by compressed gypsum (calcium sulfate).


Email This Post
Tweet This Post 
Share This Post on Facebook

Neat stuff from the NeatoShop:

  1. empty-minded
    Apr 18th, 2008 at 6:54 am

    And a pencil’s lead isn’t made of lead.

  2. stacyj
    Apr 18th, 2008 at 3:07 pm

    And baby oil is not made of …

    Oh, never mind =P

  3. Alannah
    Apr 19th, 2008 at 10:32 pm

    I want the space that this is now going to take in my mind back. I would like to replace it with my anniversary, which I keep forgetting. Thank you.

  4. llamafruit
    May 16th, 2008 at 2:25 pm

    Hi all. I stumbled upon this site and it seems fascinating.


Keep track of the comments with Comment RSS

Don't Miss: New Stuff | Bestsellers | The Cute Store
                   Funny T-Shirts

Need a gift? Get unforgettable gifts for:
Geeks | Pranksters | Kids | Hipsters | Shutterbugs
Lijit Search
Old school? Bookmark us! RSS Feed Twitter Facebook Page