Nitrogen is by far the most common impurity found in gem diamonds.

Other common impurities of clinohumite include aluminium, manganese, and calcium.

For instance, sulfur is a common impurity in steel.

The most common impurity in diamond is nitrogen, which can comprise up to 1% of a diamond by mass.

It is also a common impurity in sulfur dichloride.

Magnesium, zinc and iron are common impurities substituting for manganese.

Vinylcyclohexene is a common impurity found in butadiene upon storage due to dimerization.

The most common impurity of synthetic urea is biuret, which impairs plant growth.