https://wealthfits.com/stages-of-passing-a-kidney-stone/
The formation of stones is favored by the increase in mineral salts’ concentration or the decrease in the liquid. That holds them in solution (i.e., by a low volume of urine, often due to a reduced intake of fluids). When the salts aggregate, they first give life to the so-called crystals, form the micro-calculations, and, finally. The actual stones (which can even reach the size of a golf ball).