What Are Dark Kidney Stones Made Of. Kidney stones do not all look the same. Four primary types of kidney stones exist.
There are four types of kidney stones. Stones can be round jagged or even have branches. Most stones are yellow or brown but they can also appear tan gold or black.
Calcium oxalate uric acid struvite and cystine.
There are four types of kidney stones. The color depends on what substances make up the stone. Kidney stones or renal calculi are masses made of crystals. They vary in size from specks to peb.