Gnyssose or Gneissose: How To spell?

The word Gnyssose is misspelled against Gneissose, an adjective meaning "Having the structure of gneiss."

Word contains consecutive vowels 'EI' in between alphabets gn & ssose is misspelled as 'Y'
Wrong Spelling:  gn-y-ssose 
Correct Spelling:  gn-ei-ssose 
Find more incorrect spellings of Gneissose to spell right way.