Diamond crystallization mechanisms

1990 ◽  
Vol 26 (3) ◽  
pp. 362-365
Author(s):  
V. Ya. Slobodskoi ◽  
V. V. Sobolev ◽  
P. N. Baranov
Keyword(s):  
Diamond Crystallization

scholarly journals Diamond formation in an electric field under deep Earth conditions

2021 ◽  
Vol 7 (4) ◽  
pp. eabb4644
Author(s):  
Yuri N. Palyanov ◽  
Yuri M. Borzdov ◽  
Alexander G. Sokol ◽  
Yuliya V. Bataleva ◽  
Igor N. Kupriyanov ◽  
...  
Keyword(s):  
Electric Fields ◽  
Lithospheric Mantle ◽  
Isotope Fractionation ◽  
Diamond Formation ◽  
Mantle Minerals ◽  
Electrochemical Processes ◽  
Mantle Mineral ◽  
Deep Earth ◽  
Diamond Crystallization ◽  
Global Carbon

Most natural diamonds are formed in Earth’s lithospheric mantle; however, the exact mechanisms behind their genesis remain debated. Given the occurrence of electrochemical processes in Earth’s mantle and the high electrical conductivity of mantle melts and fluids, we have developed a model whereby localized electric fields play a central role in diamond formation. Here, we experimentally demonstrate a diamond crystallization mechanism that operates under lithospheric mantle pressure-temperature conditions (6.3 and 7.5 gigapascals; 1300° to 1600°C) through the action of an electric potential applied across carbonate or carbonate-silicate melts. In this process, the carbonate-rich melt acts as both the carbon source and the crystallization medium for diamond, which forms in assemblage with mantle minerals near the cathode. Our results clearly demonstrate that electric fields should be considered a key additional factor influencing diamond crystallization, mantle mineral–forming processes, carbon isotope fractionation, and the global carbon cycle.

Effects of Fe additive on diamond crystallization from carbonyl nickel powders-C system under HPHT condition

2015 ◽  
Vol 24 (8) ◽  
pp. 088104
Author(s):  
Yong Li ◽  
Xiao-Peng Jia ◽  
Yun-Guang Feng ◽  
Chao Fang ◽  
Li-Juan Fan ◽  
...  
Keyword(s):  
Carbonyl Nickel ◽  
Nickel Powders ◽  
Diamond Crystallization

Diamond crystallization in nature

1987 ◽  
Vol 23 (1) ◽  
pp. 83-86 ◽  
Author(s):  
V. V. Sobolev
Keyword(s):  
Diamond Crystallization

Diamond crystallization with a carbonyl nickel catalyst under high pressure and temperature

CrystEngComm ◽  
2016 ◽  
Vol 18 (11) ◽  
pp. 1924-1932 ◽  
Author(s):  
Xiaobing Liu ◽  
Xiaopeng Jia ◽  
Ming Zhao ◽  
Hong-An Ma
Keyword(s):  
High Pressure ◽  
Nickel Catalyst ◽  
High Pressure And Temperature ◽  
Carbonyl Nickel ◽  
Diamond Crystallization

Kinetic peculiarities of diamond crystallization in K-Na-Mg-Ca-Carbonate-Carbon melt-solution

2013 ◽  
Vol 55 (2) ◽  
pp. 373-376 ◽  
Author(s):  
N. A. Solopova ◽  
A. V. Spivak ◽  
Yu. A. Litvin ◽  
A. A. Shiryaev ◽  
V. A. Tsel’movich ◽  
...  
Keyword(s):  
Carbonate Carbon ◽  
Diamond Crystallization ◽  
Ca Carbonate

scholarly journals How do diamonds grow in metal melt together with silicate minerals? An experimental study of diamond morphology

2020 ◽  
Vol 32 (1) ◽  
pp. 41-55
Author(s):  
Aleksei Chepurov ◽  
Valery Sonin ◽  
Jean-Marie Dereppe ◽  
Egor Zhimulev ◽  
Anatoly Chepurov
Keyword(s):  
Natural Diamond ◽  
Diamond Growth ◽  
Chemical Compositions ◽  
Silicate Minerals ◽  
Metal Melt ◽  
Origin And Evolution ◽  
Metal Melts ◽  
Reducing Conditions ◽  
Diamond Crystallization ◽  
The Stability

Abstract. The origin and evolution of metal melts in the Earth's mantle and their role in the formation of diamond are the subject of active discussion. It is widely accepted that portions of metal melts in the form of pockets can be a suitable medium for diamond growth. This raises questions about the role of silicate minerals that form the walls of these pockets and are present in the volume of the metal melt during the growth of diamonds. The aim of the present work was to study the crystallization of diamond in a complex heterogeneous system: metal-melt–basalt–carbon. The experiments were performed using a multianvil high-pressure apparatus of split-sphere type (BARS) at a pressure of 5.5 GPa and a temperature of 1500 ∘C. The results demonstrated crystallization of diamond in metal melt together with garnet and clinopyroxene, whose chemical compositions are similar to those of eclogitic inclusions in natural diamond. We show that the presence of silicates in the crystallization medium does not reduce the chemical ability of metal melts to catalyze the conversion of graphite into diamond, and, morphologically, diamond crystallizes mainly in the form of a cuboctahedron. When the content of the silicate material in the system exceeds 5 wt %, diamond forms parallel-growth aggregates, but 15 wt % of silicate phases block the crystallization chamber, preventing the penetration of metallic melt into them, thus interrupting the growth of diamond. We infer that the studied mechanism of diamond crystallization can occur at lower-mantle conditions but could also have taken place in the ancient continental mantle of the Earth, under reducing conditions that allowed the stability of Fe–Ni melts.

Effect of sulfur concentration on diamond crystallization in the Fe–C–S system at 5.3–5.5 GPa and 1300–1370°C

2016 ◽  
Vol 54 (5) ◽  
pp. 415-422 ◽  
Author(s):  
E. I. Zhimulev ◽  
V. M. Sonin ◽  
A. M. Mironov ◽  
A. I. Chepurov
Keyword(s):  
Sulfur Concentration ◽  
Diamond Crystallization

Diamond Crystallization from an Antimony–Carbon System under High Pressure and Temperature

2015 ◽  
Vol 15 (5) ◽  
pp. 2539-2544 ◽  
Author(s):  
Yuri N. Palyanov ◽  
Yuri M. Borzdov ◽  
Igor N. Kupriyanov ◽  
Yuliya V. Bataleva ◽  
Alexander F. Khokhryakov ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure And Temperature ◽  
Diamond Crystallization ◽  
Carbon System
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