Abstract Carbonado and yakutite are both porous aggregates of polycrystalline micrometre-size diamond, with very different characters from those of monocrystalline diamond. The genesis of carbonado is very controversial, whereas yakutite is thought to have been formed by meteorite impact. Neutron activation analyses of trace elements in carbonado and yakutite indicate that their rare earth element ( REE ) abundance patterns have common characteristics: heavy REEs are not much depleted and a negative Eu anomaly is observed. These patterns are quite different from those of kimberlite and monocrystalline diamond and are similar to those of crustal materials such as shale, supporting the hypothesis of a crustal origin for carbonado and yakutite.

10.1180/minmag.1993.057.389.05

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Citations (32)

Carbon, nitrogen, argon and helium study of impact diamonds from Ebeliakh alluvial deposits and Popigai crater

Meteoritics and Planetary Science (1998)

Denis Alexander Shelkov A. B. Verchovsky H. J. Milledge Felix V. Kaminsky C. T. Pillinger

Abstract— Nineteen diamond aggregate specimens (1–2 mm in size) from impactites of Popigai crater and five diamond samples (5–7 mm in size) from Ebeliakh river placers were studied. Our investigations indicate that samples from Ebeliakh were formed in an impact event with the exception of one specimen (Y7). The carbon isotopic composition of diamonds from Popigai varies within the previously reported limits (δ 13 C, −8 to −22%); whereas, diamonds from Ebeliakh placers show heavier values of δ 13 C (−7 to −10%). All the specimens studied contain very low amounts of N, mostly <20 ppm, but a few contained up to 60 ppm. For specimens, where the quantity of N allowed reliable analysis, δ 15 N values were found to be in the range of −3.9 to +11.9%. On the basis of combined Ar and N study, it was concluded that impact diamonds studied here can be a mixture of at least two types of gas carriers ( e.g. , different diamond components). A possible explanation would be involvement of a carbon vapour deposition (CVD) process or diamond growth in the impact melt in addition to the direct graphite‐diamond shock transformation. The δ 13 C distributions and different N/ 36 Ar correlations have indicated a difference between impact diamonds from Ebeliakh and diamonds extracted from Popigai crater. This could be explained by the existence of different diamond populations formed during the Popigai impact event. On the other hand, Ebeliakh diamonds could have resulted from a separate impact event to Popigai and an alternative crater is yet to be found.

Carbon fibers

Diamond type

Deposition

10.1111/j.1945-5100.1998.tb01705.x

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Citations (19)

Primary sources of diamonds in the Birim area, Ghana

International Kimberlite Conference Extended Abstracts: 2008 (2019)

Felix V. Kaminsky G Gorzynsky L Sablukova S. M. Sablukov

The Birim area is the main diamondiferous area in Ghana.It is situated in the Birim River drainage basin, and is dominated by metamorphosed greywackes, phyllites, crystalline schists, metamorphosed basic, ultrabasic and pyroclastic rocks of the Birim formation, granites and granodiorites and dykes of acid rocks.Diamondiferous placers are known to be present in some areas of the river's watercourse and along its left and right affluents.More than 100 million carats

Primary (astronomy)

10.29173/ikc2744

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Citations (1)

Prognostication of primary diamond deposits

Journal of Geochemical Exploration (1995)

Felix V. Kaminsky A.A. Feldman V.A. Varlamov Alexey Boyко L.N. Olofinsky

Block structure

10.1016/0375-6742(94)00019-8

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Citations (25)

First find of merrillite, Ca3(PO4)2, in a terrestrial environment as an inclusion in lower-mantle diamond

American Mineralogist (2021)

Felix V. Kaminsky D. A. Zedgenizov

Abstract Merrillite, ideally Ca18Na2Mg2(PO4)14 (Dana No: 38.03.04.04; Strunz No: 08.AC.45), an analog to synthetic tricalcium phosphate β-Ca3(PO4)2, was identified as an inclusion in lower-mantle diamonds from the Rio Soriso area, Brazil. It was associated with former bridgmanite, CaSi- and CaTi-perovskites, and ferropericlase. This is the first report of merrillite in a terrestrial environment; previously, it was known only in meteorites and lunar rocks. The compositions of merrillite vary in different localities; the Rio Soriso sample was enriched in SO3 (2.03 wt%). Merrillite from lower-mantle diamonds may be a retrograde phase of the tuite [γ-Ca3(PO4)2]. Owing to their crystal structures, both merrillite and tuite may be important potential hosts for rare earth elements (REE) and large ion lithophile elements (LILE), including Sr and Ba, in the deep Earth. The find of merrillite suggests a larger variety of mineral species in the lower mantle than previously assumed.

Lithophile

Lile

Silicate perovskite

10.2138/am-2022-8175

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STEM EDX Nitrogen Mapping of Nanoinclusions in Milky Diamonds from Juina, Brazil, Using a Windowless Silicon Drift Detector System

Analytical Chemistry (2016)

J. Rudloff-Grund Frank E. Brenker Katharina Marquardt Felix V. Kaminsky Anja Schreiber

Energy-dispersive X-ray spectroscopy (EDX) performed using scanning transmission electron microscopy (STEM) in combination with a windowless detector setup allows high-resolution imaging and chemical composition mapping even of light elements present in low concentrations. The used TEM-system combines a field emission electron source with four silicon drift detectors allowing for high detection sensitivity. We used this enhanced system to investigate 20 to 200 nm sized inclusions in milky diamonds from Rio Soriso, Juina area, Brazil. The diamonds act as a chemical inert container and therefore protect their inclusions from further chemical reactions with their surroundings. We visualize the presence and distribution of nitrogen within focused ion beam (FIB) slices containing these nanoinclusions. The investigation of these specific diamonds may open a new window to deeper parts of the Earth (>660 km) as they represent pristine material of this deep mantle environment.

Silicon drift detector

10.1021/acs.analchem.6b00373

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Citations (11)