Find some common objects and talk about what elements they may be made of.

Diamonds: diamonds. Pencil lead: Graphite.

Diamonds are commonly known as "Jin Gangzuan". That is, we often say that the original diamond is a mineral composed of carbon, which is an allotrope of carbon. Diamonds are the hardest substance in nature. Diamonds are widely used, such as handicrafts and industrial cutting tools. Graphite can form synthetic diamond at high temperature and high pressure. Pencil lead: Graphite.

The main component of pencil lead is graphite. In fact, the refill of a pencil is made of graphite and clay mixed in a certain proportion.