red phosphorus

Wiktionary

1. n. a stable allotrope of phosphorus; used in the manufacture of safety matches, pesticides etc

GNU Webster's 1913

1. n. an allotropic modification of phosphorus, obtained as a dark red powder by heating ordinary phosphorus in closed vessels. It is not poisonous, is not phosphorescent, and is only moderately active chemically. It is valuable as a chemical reagent, and is used in the composition of the friction surface on which safety matches are ignited.
2. adj. See under Phosphorus.