Cleavage Planes in Halite
November 28, 2004
One of my Earth Science students (at the Steward School in Richmond, Virginia) was having difficulty with the idea of halite having three cleavage planes at right angles to each other -- a teachable moment! I went across the hall to our middle school science lab and found a really poorly shaped (but very clear) specimen of halite, and retrieved a hammer and a box-cutter blade. I stabilized the specimen on the best base I could find, and gave it a whack. One good plane emerged, turning it 90 degrees. I struck again. The small piece that flew off was not a perfect cube, but had one perfect cubical corner. Understanding was instantaneous. The class decided I should become a diamond cutter for my next career.
Photographed with my Canon S410 camera.