1. Struvite -Struvite stones are composed of magnesium, ammonium, and phosphate (MAP). They are found most commonly in women and may recur rapidly. They frequently present as renal staghorn calculi and rarely present as ureteral stones except after surgical intervention (Figure 16–5). Struvite stones are infection stones associated with urea-splitting organisms,  including Proteus, Pseudomonas, …