Experimental and theoretical evidence for surface-induced carbon and nitrogen fractionation during diamond crystallization at high temperatures and high pressures. / Reutsky, Vadim N.; Kowalski, Piotr M.; Palyanov, Yury N. et al.
In: Crystals, Vol. 7, No. 7, 190, 01.07.2017.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Experimental and theoretical evidence for surface-induced carbon and nitrogen fractionation during diamond crystallization at high temperatures and high pressures
AU - Reutsky, Vadim N.
AU - Kowalski, Piotr M.
AU - Palyanov, Yury N.
AU - Wiedenbeck, Michael
PY - 2017/7/1
Y1 - 2017/7/1
N2 - 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.
AB - 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.
KW - Carbon isotopes
KW - Crystal chemistry
KW - Experiment
KW - Fractionation
KW - High pressure
KW - High temperature
KW - Mixed-habit diamond crystallization
KW - Nitrogen impurity
KW - SIMS
KW - Surface structure
KW - HABIT
KW - nitrogen impurity
KW - UDACHNAYA-EAST KIMBERLITE
KW - DEEP MANTLE
KW - HIGH P
KW - experiment
KW - CRYSTAL-GROWTH
KW - SYNTHETIC DIAMOND
KW - mixed-habit diamond crystallization
KW - fractionation
KW - crystal chemistry
KW - IMPURITY
KW - surface structure
KW - high pressure
KW - high temperature
KW - NATURAL DIAMOND
KW - GROWTH-SECTOR DEPENDENCE
KW - carbon isotopes
KW - ISOTOPE FRACTIONATION
UR - http://www.scopus.com/inward/record.url?scp=85021660564&partnerID=8YFLogxK
U2 - 10.3390/cryst7070190
DO - 10.3390/cryst7070190
M3 - Article
AN - SCOPUS:85021660564
VL - 7
JO - Crystals
JF - Crystals
SN - 2073-4352
IS - 7
M1 - 190
ER -
ID: 10096327