The /ɒ/ vowel is spelled <o>, or <a> after <w> or <qu> in wad and quad. The /ɪə/ diphthong is spelled <ear>, <eir>, <eer>, or <ir> in the loan word kirsch. The dictionary search also found the pair proton/protean, but it is questionable whether protean contains the /ɪə/ diphthong or is a three-syllable word.
This contrast is between a short back vowel and a front centering diphthong. It is not a problem for any learners.
Interesting pairs include:
porridge peerage
quarry query
warrior wearier
The density value is small at 0.67%. The pairs make 21 semantic contrasts, giving a high loading of 77.8%.
body beardie bodied bearded clod cleared cosh kirsch Dolly dearly fosse fierce god geared horror hearer horrors hearers Molly merely nod neared oz ears pod peered porridge peerage proton protean quad queered quarry query quarried queried quarries queries quarrying querying rod reared shod sheared wad weird wadi weirdie wadis weirdies warrior wearier was weirs
John Higgins, Shaftesbury, November 2009