Standard Lemma guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
No pronunciation record was provided for this word.
noun
An eye shape of concentric coloured optical fringes seen on a conoscopic interference pattern surrounding an optical axis. For biaxial minerals there are a pair of circles, like eyes.
Definition source: English Wiktionary via Wiktextract
Qualifier: microscopy
Topics: chemistry, geography, geology, mineralogy, natural-sciences, physical-sciences
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
History
Coined by A. Johannsen on page 420 in A Manual of Petrographic Methods McGraw-Hill 1918
