Red phosphorus, in the form of a very fine red/brown powder. Ultra fine particles stick to the glass and these have a rusty appearance. This allotrope of phosphorus is rather inert at room temperature and is not toxic. At elevated temperatures, it is quite flammable. This form of phosphorus can be handled safely.

Red phosphorus also is available as coarse particles. In that form it looks more purple/brown than red, but still it is called red phosphorus.

This is the white allotrope of phosphorus. It is exceedingly poisonous (LD50 for a human being is approximately 0.5 mg per kg body weight) and inflames in air at warm room temperature. While this sample was transferred very quickly from its original container to this display vial it already emitted some white smoke. The white phosphorus is stored under water and can only safely be stored in that way.