Ca–Oxalate>>>70% the most common
OK, now the explanation. The most common and the least common start with the same letter “C”. The next letter after “C” is “a” for Ca-Oxalate and Ca-Phosphate, so lets put them in the beginning of the list. The next letter after “C” is “y” for Cysteine, so lets put it in the end of the list. If you wonder between Ca-Oxalate and Ca-Phosphate, which one comes first, just look at the letters “O” and “”P”. Which one comes first? Of course Ca-Oxalate, which is the most common kidney stone with 70%. OK, we left with two more type of stones: Magnesium/Aluminum/Phospate and Uric acid. They are also in an alphabetical order, so there is nothing more to say.
Source: USMLE Step 2 CK Lecture Notes: Internal Medicine