How many letters does the top answer for “containing, or having the nature of, marcasite.” have?

The most common answer is marcasitic (10 letters).

Crossword clue: containing, or having the nature of, marcasite.

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

marcasitic 10 letters web-def

Containing, or having the nature of, marcasite.

marcasitical 12 letters web-def

Containing, or having the nature of, marcasite.