Gnyssoid or Gneissoid: How To spell?

The word Gnyssoid is misspelled against Gneissoid, an adjective meaning "Resembling gneiss; having some of the characteristics of gneiss; -- applied to rocks of an intermediate character between granite and gneiss, or mica slate and gneiss."

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