The diamond Diamond crystal consists of interlocking hexagons with an underlying tetrahedral symmetry. Construction Begin by having students construct a tetrahedron. Have the students take out one gumdrop and four toothpicks. Ask them to stick the toothpicks in the gumdrop so that the ends of the toothpick are as far apart as possible, as if they repel each other. This is a model of the bonds in a carbon atom.
Students tend to keep the toothpicks in one plane.
Show them that they can get the toothpicks further apart if they think in three dimensions. If they hold the gumdrop in the center of the tetrahedron and have the toothpicks stick out through the centers of the four triangles, they will create the correct model. Now begin the construction of the diamond crystal by taking six toothpicks and six gumdrops and sticking them together to make a hexagon. Take three toothpicks and three gumdrops. Stick the toothpicks straight up in three of the gumdrops of the hexagons, choosing alternate gumdrops so that each gumdrop with a toothpick has gumdrops without toothpicks on either side.