Crossword clue: a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known

The most common answer is osmium (6 letters).

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

Possible answers

osmium 6 letters wn-def

a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known