Syllable division and stress derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
microcrystalline is an adjective meaning "containing crystals that are visible only under a microscope". It carries one recorded sense.
containing crystals that are visible only under a microscope
Definitions, synonyms and semantic relations for microcrystalline come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.