Not true about 'Struvite Stones' is :

Ans. is 'd' ie Usually seen in acidic urine " Struvite stone tends to grow in alkaline urine * esp. when proteus organisms are present which split urea to ammonia" Types of Renal CalculusCalcium oxalate calculus (Most common*) they have hard, small and jagged surfacePhosphate calculus calcium phosphate but can be combined with ammonium and magnesium to form the triple phosphate calculus * ie Calcium ammonium magnesium phosphate also k/a struvite stones. smooth and dirty white and solitary*.seen in alkaline urine esp with proteus infection which split urea to ammonia. this type of calculus may enlarge to fill all or most of the renal collecting system forming a staghorncalculus*.Uric acid and urate calculus these are radiolucent*Form in acidic urine - Most responsive to lithotripsyCystein stones uncommon, seen in cystinuria appear only in acidic urine*they are pink to yellow when first removed but they change colour to a greenish hue when exposed to air. extremely hard stones are relatively resistant to fragmentation by ESWLXanthine calculi are radiolucent*are secondary to a congenital deficiency of xanthine oxidaseIndinavir calculiIndinavir is a protease inhibitor used in AIDS patients. It results in calculi in ~6% pt. who use. Indinavir. Indinavir calculi are radiolucent.Rare CalculiSilicate stones associated with the long term use of antacids containing silicaTriamterene stones associated with antihypertensive medications containing triamterene are radiolucent