Cuboctahedral type Ib diamonds in ophiolitic chromitites and peridotites: the evidence for anthropogenic contamination

Here we present trace element compositions of synthetic diamonds, which show spectacular similarity with the compositions of metallic inclusions in type Ib cuboctahedral diamonds in ophiolitic chromitites and peridotites. The compositions of inclusions in synthetic and ophiolite diamonds closely correspond to Ni:Mn:Co = 70:25:5 in wt.%, which is the most widely used catalyst for HPHT growth of synthetic diamonds in China. Thus, we claim for thorough reconsideration of diamonds in ophiolitic rocks and emphasize that most of them appear by anthropogenic contamination.