Crossword clue: the principal form of iron ore; consists of ferric oxide in crystalline form; occurs in a red earthy form

The most common answer is haematite (9 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

haematite 9 letters wn-def

the principal form of iron ore; consists of ferric oxide in crystalline form; occurs in a red earthy form

hematite 8 letters wn-def

the principal form of iron ore; consists of ferric oxide in crystalline form; occurs in a red earthy form