Spess or Speiss: How To spell?

The word Spess is misspelled against Speiss, a noun meaning "A regulus consisting essentially of nickel, obtained as a residue in fusing cobalt and nickel ores with silica and sodium carbonate to make smalt."

Word contains consecutive vowels 'EI' in between alphabets sp & ss is misspelled as 'E' as letter 'I' is phonetically ignored
Wrong Spelling:  sp-e-ss 
Correct Spelling:  sp-ei-ss 
Explore spell check of Speiss to spell without errors.