Diamondiferous garnet harzburgites from the Finsch kimberlite, Northern Cape, South Africa

K. S. Viljoen, P. M. Swash, M. L. Otter, D. J. Schulze, P. J. Lawless

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


Two xenoliths of garnet harzburgite from the Finsch kimberlite, South Africa, have been found to contain diamond. One of the xenoliths has mineral compositions typical of low-T coarse textured garned peridotites, whereas minerals in the other are similar but not identical to most peridotite-suite minerals included in diamonds, especially in the low-CaO content of garnet. Geothermobarometric calculations show both xenoliths equilibrated at temperatures above 1,100°C and pressures>55 kbar, which is near the low-pressure end of the range of equilibration conditions for diamond-free garnet lherzolites and garnet harzburgites from Finsch. The chemistries of the minerals in the two rocks are distinctly different to most of the mineral inclusions in Finsch diamonds. This, as well as the different δ13C compositions between xenolith diamonds (-2.8 to-4.6‰) and diamonds in the kimberlite (generally<-4.3‰) suggest different origins or sources for the diamonds.

Original languageEnglish
Pages (from-to)133-138
Number of pages6
JournalContributions to Mineralogy and Petrology
Issue number1
Publication statusPublished - Mar 1992
Externally publishedYes

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology


Dive into the research topics of 'Diamondiferous garnet harzburgites from the Finsch kimberlite, Northern Cape, South Africa'. Together they form a unique fingerprint.

Cite this