FIGURE 2 Re-Os isochron diagram for sulfide inclusions in diamonds and putative host harzburgites from the Panda kimberlite pipe, Slave craton, NWT, Canada (after Westerlund et al. 2006). The sulfide inclusions (red squares) regress to an age of 3.52 ± 0.17 Ga (with 4 additional inclusions off scale) and have an elevated initial ¹⁸⁷Os/¹⁸⁸Os isotope composition compared to a 3.5 Ga mantle (black line). With one exception, harzburgites that host the diamonds (green crosses) have ¹⁸⁷Os/¹⁸⁸Os ratios above primitive mantle values, but less so than the diamonds. The upper left panel shows a polished Panda diamond plate with 4 inclusions in their "rosette" fracture system. Shown in the upper right is a typical scanning electron micrograph of a released inclusion prior to dissolution, chemical separation of the Re and Os, and mass spectrometry.