The % recovery values less than 100 % for K-feldspar INSs may be due to loss of K-feldspar to the vessel walls during density gradient centrifugation. In addition, some of the K-feldspar INSs may have been discarded with the density gradient medium if they were small in size and therefore not able to sediment completely (See SI, Section 1, Table ). K-feldspar loss could also occur if the pellet is disturbed when removing the density gradient medium, leading to K-feldspar INSs reentering the density gradient medium and being discarded.