Fresh frozen plasma (FFP) and cryoprecipitate, often called “cryo” for short, are transfused to patients who have abnormal or low levels of blood clotting proteins, such as in hemophilia.
It's only achievable using irradiation, which creates an extremely fine occlusion within the stone that's virtually impossible to detect unless you're looking for it.
Some species secrete these by themselves while others use things they find in their environments like grains of sediment, skeletons of other microbes and sometimes even microplastics.