The stones formed in human kidney consist mostly of

The vast majority of renal calculi are calcium-containing, and calcium oxalate is the single most common stone constituent. Large studies and reviews report that about three-quarters of urinary calculi contain calcium and that roughly half of stones are composed predominantly of calcium oxalate [1]. Clinical resources list calcium oxalate (and less commonly calcium phosphate) as the dominant stone types and explain formation by supersaturation of urine with calcium and oxalate leading to crystal precipitation [3]. The other options listed (sodium acetate, magnesium sulphate, or elemental calcium) are not typical principal compositions of human kidney stones; magnesium-containing infection stones are usually magnesium ammonium phosphate (struvite) and are less frequent.

Sources

1. [1] https://spj.science.org/doi/10.34133/jbioxresearch.0002
2. [2] https://www.hopkinsmedicine.org/health/conditions-and-diseases/kidney-stones
3. [3] https://www.kidney.org/kidney-topics/calcium-kidney-stones