Figure 4.

A comparison of the P-T estimate made for the compression of coesite inclusions in a Venezuelan diamond (solid diamond) with estimates made by several methods for a variety of peridotitic diamonds. Open diamond, compression of olivine inclusions (19). Shaded field, touching diamond inclusions, mostly orthopyroxene + garnet, with one extreme point omitted (44). Open circles, perdotite xenoliths containing diamond, worldwide (garnet + olivine/PBKN thermobarometer, discussed by Pearson et al., ref. 45). Data for diamondiferous peridotites are from Dawson and Smith (55), Boyd and Finnerty (56), Shee et al. (57), and Viljoen et al. (23). The graphite-diamond boundary (G/D) is from Kennedy and Kennedy (14). The coesite-stishovite boundary (C/S) is from Zhang et al. (58).