| This qualifier is the general description for the common allotropes of elemental phosphorus. |
| It is the interaction of the allotropes of iron with the alloying elements, primarily carbon, that gives steel and cast iron their range of unique properties. |
| Among different forms of carbon, graphene is one of the widely studied allotropes. |
| The plutonium pits of nuclear weapons employ an alloy with gallium to stabilize the allotropes of plutonium. |
| The presence of these many allotropes makes machining plutonium very difficult, as it changes state very readily. |
| Arsenic has two allotropes, yellow arsenic and metallic arsenic, which is brittle. |
