--> Metacinnabarite has double "nn" is mispronounced as "n"
Remember double 'NN' in between the strings metaci & abarite which should not be misspelled with single 'N'
Wrong Spelling:  metaci-n-abarite 
Correct Spelling:  metaci-nn-abarite 
Find more wrongly spelled words of Metacinnabarite to spell it well.