How many letters does the top answer for “of or pertaining to hematite.” have?

The most common answer is oligist (7 letters).

Crossword clue: of or pertaining to hematite.

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

oligist 7 letters web-def

Hematite or specular iron ore; -- prob. so called in allusion to its feeble magnetism, as compared with magnetite.

oligistic 9 letters web-def

Of or pertaining to hematite.

of or pertaining to hematite, or resembling it. 67% similar → hematitic