Gneis or Gneiss: How To spell?
The word Gneis is misspelled against Gneiss, a noun meaning "A crystalline rock, consisting, like granite, of quartz, feldspar, and mica, but having these materials, especially the mica, arranged in planes, so that it breaks rather easily into coarse slabs or flags. Hornblende sometimes takes the place of the mica, and it is then called hornblendic / syenitic gneiss. Similar varieties of related rocks are also called gneiss."
Gneiss has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  gnei-s  Correct Spelling:  gnei-ss 
Find more wrongly spelled words of Gneiss to spell it well.