Experimental and theoretical evidence for surface-induced carbon and nitrogen fractionation during diamond crystallization at high temperatures and high pressures

Vadim N. Reutsky, Piotr M. Kowalski, Yury N. Palyanov, Michael Wiedenbeck

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)

Abstract

Isotopic and trace element variations within single diamond crystals are widely known from both natural stones and synthetic crystals. A number of processes can produce variations in carbon isotope composition and nitrogen abundance in the course of diamond crystallization. Here, we present evidence of carbon and nitrogen fractionation related to the growing surfaces of a diamond. We document that difference in the carbon isotope composition between cubic and octahedral growth sectors is solvent-dependent and varies from 0.7‰ in a carbonate system to 0.4‰ in a metal-carbon system. Ab initio calculations suggest up to 4‰ instantaneous 13C depletion of cubic faces in comparison to octahedral faces when grown simultaneously. Cubic growth sectors always have lower nitrogen abundance in comparison to octahedral sectors within synthetic diamond crystals in both carbonate and metal-carbon systems. The stability of any particular growth faces of a diamond crystal depends upon the degree of carbon association in the solution. Octahedron is the dominant form in a high-associated solution while the cube is the dominant form in a low-associated solution. Fine-scale data from natural crystals potentially can provide information on the form of carbon, which was present in the growth media.

Original languageEnglish
Article number190
Number of pages14
JournalCrystals
Volume7
Issue number7
DOIs
Publication statusPublished - 1 Jul 2017

Keywords

  • Carbon isotopes
  • Crystal chemistry
  • Experiment
  • Fractionation
  • High pressure
  • High temperature
  • Mixed-habit diamond crystallization
  • Nitrogen impurity
  • SIMS
  • Surface structure
  • HABIT
  • nitrogen impurity
  • UDACHNAYA-EAST KIMBERLITE
  • DEEP MANTLE
  • HIGH P
  • experiment
  • CRYSTAL-GROWTH
  • SYNTHETIC DIAMOND
  • mixed-habit diamond crystallization
  • fractionation
  • crystal chemistry
  • IMPURITY
  • surface structure
  • high pressure
  • high temperature
  • NATURAL DIAMOND
  • GROWTH-SECTOR DEPENDENCE
  • carbon isotopes
  • ISOTOPE FRACTIONATION

Fingerprint

Dive into the research topics of 'Experimental and theoretical evidence for surface-induced carbon and nitrogen fractionation during diamond crystallization at high temperatures and high pressures'. Together they form a unique fingerprint.

Cite this