Gneyssic or Gneissic: How To spell?

The word Gneyssic is misspelled against Gneissic, an adjective meaning "Relating to, or resembling, gneiss; consisting of gneiss."

Word contains consecutive vowels 'EI' in between alphabets gn & ssic is misspelled as 'EY'
Wrong Spelling:  gn-ey-ssic 
Correct Spelling:  gn-ei-ssic 
Find more wrongly spelled words of Gneissic to spell it well.