Crossword clue: a mineral of a yellowish color, consisting chiefly of silica, glucina, manganese, and iron, with a little sulphur.

The most common answer is helvine (7 letters).

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

Possible answers

helvine 7 letters web-def

A mineral of a yellowish color, consisting chiefly of silica, glucina, manganese, and iron, with a little sulphur.

helvite 7 letters web-def

A mineral of a yellowish color, consisting chiefly of silica, glucina, manganese, and iron, with a little sulphur.