Impact diamonds in an extravagant metal piece found in Paraguay

Abstract

Around 70 km SSE of Chovoreca Hill (Paraguay), a pitcher-like metal piece weighing approximately 303 kg was found. Several studies have been carried out on this piece. Metallographic examination resembles cast iron that presents eutectoid microtextures, but the metal showed Neumann lines. Small fragments of the piece were diluted in concentrated HCl and with this it was possible to obtain colorless crystals, with size ranging from 10 μm to 1 mm, approximately; SEM/EDS studies showed that major element present is carbon which suggests the presence of diamonds. Raman spectroscopy proved that crystals are diamonds, that showing bands in the “lonsdaleite/diamond zone”, further, the results also showed bands that accuse that the carbon of the diamonds are of meteoritic origin. From the calculus of the FWHM with values around to 42-373 cm-1 centered on 1282 cm-1 peak could be an indication of a very powerful impact that would have formed the diamonds.

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Impact diamonds in an extravagant metal piece found in Paraguay
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5
HISTORIA NATURAL
Tercera Serie Volumen 10 (2) 2020/5-15
ISSN 0326-1778 (Impresa)
ISSN 1853-6581 (En Línea)
Jaime L.B. Presser1, Magna Monteiro2 and Andrea Maldonado3
1International Association for Geoethics, Paraguay National Chapter, Asunción, Paraguay.
presserjaime@gmail.com
2Laboratorio de Bio y Materiales – Labioymat, Facultad Politécnica – FP, Universidad Nacional de
Asunción, San Lorenzo, Paraguay. mmonteiro@pol.una.py
3Facultad Politécnica – UNA, San Lorenzo, Paraguay. andreabeatrizmn@gmail.com
IMPACT DIAMONDS IN AN EXTRAVAGANT
METAL PIECE FOUND IN PARAGUAY
Diamantes de impacto en una pieza de metal extravagante encontrada en Paraguay

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
6
Presser j., Monteiro M. and Maldonado a.
Abstract. Around 70 km SSE of Chovoreca Hill (Paraguay), a pitcher-like metal piece weighing
approximately 303 kg was found. Several studies have been carried out on this piece. Metallographic
examination resembles cast iron that presents eutectoid microtextures, but the metal showed
Neumann lines. Small fragments of the piece were diluted in concentrated HCl and with this it was
possible to obtain colorless crystals, with size ranging from 10 μm to 1 mm, approximately. SEM/
EDS studies showed that major element present is carbon; which suggests the presence of diamonds.
Raman spectroscopy proved that crystals are diamonds, that showing bands in the “lonsdaleite/
diamond zone”, further, the results also showed bands that accuse that the carbon of the diamonds
are of meteoritic origin. From the calculus of the FWHM with values around to 42-373 cm-1 centered
on 1282 cm-1 peak could be an indication of a very powerful impact that would have formed the
diamonds.
Key words. Iron-meteorite, SEM/EDS, Raman spectroscopy, impact-diamonds, Paraguay.
Resumen. Alrededor de 70 km al SSE del Cerro Chovoreca (Paraguay), se encontró una pieza de
metal similar a un cántaro que pesaba aproximadamente 303 kg. Se han realizado varios estudios
sobre esta pieza. El examen metalográco sugiere semejanza con el hierro fundido donde se
observan micro-texturas eutectoides; sin embargo el metal muestra líneas de Neumann. Pequeños
fragmentos de la pieza se diluyeron en HCl concentrado y con esto fue posible obtener cristales
incoloros, con tamaños que varían aproximadamente de 10μm a 1mm. Los estudios de SEM/EDS
mostraron que el elemento principal presente es el carbono; lo que sugiere la presencia de diamantes.
La espectroscopía Raman demostró que los cristales son diamantes, que muestran bandas en la
“zona de lonsdaleita/diamante”, además, los resultados también muestran bandas que acusan que el
carbono de los diamantes es de origen meteorítico. A partir del cálculo de la FWHM, con valores de
alrededor de 42-373 cm-1, centrados en el pico de 1282 cm-1 se interpreta como siendo una indicación
de que un impacto muy potente habría formado los diamantes.
Palabras clave. Meteorito de hierro, SEM/EDS, espectroscopía Raman, diamantes de impacto,
Paraguay.

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IMPACT DIAMONDS IN METAL PIECE FROM PARAGUAY
7
INTRODUCTION
According to various database sources
of collections or records of meteorite falls
around the world (Prior, 1923; Grady, 2000
and Meteoritical Bulletin Database, 2013) it
is found that in Paraguay two meteorites
would have fallen: The meteorite Ipacaraí,
qualied by as doubtful, which fell shortly
before 1877 at coordinates 25 ° 18’S, 57 °
16’W. And the meteorite Villarica, fallen in
1925 at coordinates 25° 50’S, 56° 30’W, with
status qualied as ocial.
Metallic meteorites, but without published
studies, were also found: Santaní; Ybycui;
Puentesiño and Defensores del Chaco.
This work focuses on one more metal
piece of about 303 kg (Figure 1) that it
would be an iron meteorite (Presser, 2019)
studying in him the presence of impact
diamonds (mainly focus); and so point-
ing the probable meteoritic nature. These
studies will be supported by routine of
elemental petrographic analytical tech-
niques, SEM/EDS and Raman spectrosco-
py. Metal piece that was found about 70
km SE of Chovoreca Hill (Department of
Alto Paraguay, Chaco, Paraguay; Figure 2)
in the year 2002 (hereafter referred to as
the Met.CCh.) where the approximate co-
ordinates of the nding would be: -19° 44’
43” and -58° 35’ 58”.
METHODOLOGY
For the study of Met.CCh., some thin sec-
tions were cut with diamond cuing discs.
Figure 1 - Current form of the Met.CCh. seen as a
probable meteorite, unearthed by the farmer Justo
López in 2002, about 70 km to the SSE of Chovoreca
Hill, Department of Alto Paraguay.
Figure 2 - Approximate location of the discovery site of the metallic piece focus of this work (Met.CCh.) Approximate
coordinates of the finding: -19° 44’ 43” and -58° 35’ 58”.

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
8
Presser j., Monteiro M. and Maldonado a.
The piece was subjected to polishing of
the at surface (with sandpaper 1500 and
3000 for metals) until a ne and shiny sur-
face was achieved. After this, the surface
was chemically aacked with Nital (1 of
concentrated HNO3 and 4 of pure alco-
hol) for about 3 minutes. The images of
the polished section were taken using re-
ected light. Some petrographic and other
details were recorded through macro and
micrographs images.
Met.CCh. fragments were diluted and
kept at rest for two days in concentrated
HCl for the analysis of insoluble residues
(graphite, “diamonds”, etc.). The residue
was washed in water and then dried in
alcohol. The material was studied in high
magnication loupe.
Samples of the dierent parts of the me-
teorite were taken and analyzed by Scan-
ning Electron Microscopic (SEM/EDS) of
the ZEISS brand, EVO-15 model, belong-
ing to the Bio and Materials Laboratory
of the Polytechnic School of the National
University of Asuncion. These analyzes
were carried out in order to evaluate the
possible existence of dierent surface
morphologies, in addition, EDS analyzes
were also carried out to identify the chem-
ical composition of these surfaces.
The Raman analysis were performed
using a portable Raman spectrometer of
the Paleontology laboratory of the Faculty
of Sciences Exact and Natural of the Na-
tional University of Asunción, Paraguay,
of the WTek iRaman brand, BWS415-785S
model, which has a 785nm laser diode ex-
citation source as maximum power and
a CCD detector (charged couple device)
with an amount of 2048. The SpectraG-
ryph 1.2 software was used to process the
information from the Raman spectroscopy
data.
RESULTS
Petrographic observations. The Met.CCh.
is constituted of a mass of about 303 kg
which in its present form resembles a pitch-
er (Figure 1), one of its edges presents a cut
of 30% of its volume, approximately. On
the exposed surface is possible to view thin
oxidation layers.
Although the Met.CCh. at rst sight does
not present any roughness product of the
probable friction fusion upon entry into
the terrestrial atmosphere. Nevertheless,
rusty islands of Neumann bands of the
outer face were seen. In addition, was ob-
served in some fragments, the presence of
sub millimeter graphite spheres. On non-
weathered surfaces, exposed by breakage,
there is a medium-sized apparent granu-
larity made of metal and visible graphite
straws.
The aack with Nital allowed observing
an engraving zebra skin format that is re-
produced in the Figure 3a. Metallographic
examination of polished section indicated
that at rst glance the Met.CCh. texturally
resembles cast iron; and that presents very
visible eutectoid microtextures (Figure 3a).
Nevertheless a some detailed observation,
of the same sample, in reected light al-
lowed recognizing that the fragment is an
association of shiny metal (that showed
Neumann lines; Figure 3b) and portions of
nodules/shapes of sausage or amoebas (1-2
mm) of gray metal (Figure 3a); that mak-
ing remember the “cloudy zone” (Muf-
takhetdinova et al., 2019).
SEM/EDS observations. In the Figure 4
shows SEM images that present two dier-
ent topography regions well dene where
the matrix components are carbon (dark)
in one region and iron (gray slight) in the
other. The dark region presents a smooth
structure rich in carbon (graphite) of about
5 to 20 microns of size, partly overgrowth

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IMPACT DIAMONDS IN METAL PIECE FROM PARAGUAY
9
by SiC. Others measured elements were
silicon, zirconium and sulphur.
As well as, in the Figure 5, we present
some SEM images details of the micro-
structures the Met.CCh. In gure 5a, it
is possible to appreciate the diamonds
(which will be commented on next item)
incrusted, inside the circle, and increased
in the upper left corner. The (plessite
like) ne plates/lamellar structure of the
Ni-poor (according to partial analyzes)
“kamacite” can be seen in Figure 5b,
which stands out for its robust appear-
ance with visible planes with thickness
less than 5μm. On the other hand, the Fig-
ure 5c shows the hexagonal graphite mi-
crostructural sheets with grains between 5
to 10 μm of size.
Figure 3 - Met.CCh. microtextures presents in (a) stands out large size of graphite flake in dendrites form
cut across zebra skin format of round-shapes “cloudy zone” (nodules/forms of sausage or amoebas of
1-2 mm) embedded in metal matrix. (b) Neumann lines (80x). The photographs were taken with a slight
inclination of the sample.
Figure 4 - SEM image and EDS map of different region of the Met.CCh. A: micro-textural “Kamacite” (Fe, green color)
structure (200µm – 300x) and B: graphite (C, red color) hexagonal sheets (30µm – 1.5kx).

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
10
Presser j., Monteiro M. and Maldonado a.
Impact Diamonds. Jones et al. (2016; and
those referred to by them) commented
about interpretation of Raman spectra of
“lonsdaleite” saying that “the strong char-
acteristic Raman peak of cubic diamond at
Figure 5 - SEM image of different morphology regions
A: red cycle indicates the micro-diamonds incrusted;
B: fine plates/lamellar metal and C: graphite hexagonal
sheets layers.
1332 cm-1 is often used to diagnose the pres-
ence of this phase, even when it is present as
nanocrystals and in trace quantities within
mineral samples. Subtle shifts in the peak
position along with peak broadening can
reveal the presence of non-isotropic strains,
due to impurity content or structural de-
fects within the samples. The occurrence of
broadening as well as shifts in the peak po-
sition have also been interpreted as indicat-
ing the presence of “lonsdaleite”, or mixed
cubichexagonal polytype structures, within
natural and laboratory prepared samples”.
The rst reports of “hard particles” in the
Canyon Diablo meteorite dates to 1891, and
they were identied as diamond by X-ray
diraction in 1939 (Garvie & Nemeth, 2009).
Later X-ray diraction studies showed that
the Canyon Diablo “diamonds” are com-
posed of various proportions of diamond,
lonsdaleite, and graphite (Miyamoto, 1993;
Garvie et al, 2009). ALHA 77287 is the anoth-
er well-documented case for the occurrence
of diamonds in iron meteorites (Clarke et al.,
1981) that O et al. (1982) analyzed for abun-
dance and composition of cosmogenic noble
gases that results agree with the conclusion
of Clarke et al. (1981), based on textural evi-
dence, that the ALHA 77287 diamonds were
not produced during the impact with the
earth. They rather appear to be the result of
some shock event earlier in the history of the
meteoroid (O et al., 1982).
The Met.CCh. fragments of which were di-
luted in concentrated HCl produced residue
consisted of graphite, and color less (some
as milk-like) grains recognized as diamond
by their “adamantine” luster. The SEM/EDS
study was performed for grains that conrm
that the major element is carbon. As well as
the optical and SEM/EDS exam showed that
the grains range in size from 10 μm to near 1
mm. Most grains are anhedral with angular,
rounded, or curved surfaces. Some of the
larger grains show crude layering (Figure 5a
and 6).

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IMPACT DIAMONDS IN METAL PIECE FROM PARAGUAY
11
Figure 6 - Impact diamonds of the Met.CCh. The fragments of the Met.CCh. which were diluted in concentrated HCl
produced residue of colorless (some as milk-like) grains recognized as diamond, as in A. In B a SEM/EDS image
of large crystals in A study that confirmed that the major element is carbon, partly overgrowth by SiC (moissanite).
Figure 7 - Representative four selected Raman spectra from Met.CCh (raw information). Abscissa (wavenumber)
in cm-1 and ordinate (intensity). A: The Spectrum No. 15, 48 and 49 shows an intense band between 1190-1390
cm-1 and displays the extra peaks (see comments in the text). The other two Spectrum No. 18 and 22 although
less intense, but also describe similar characteristics. In B the values of the main peaks have been plotted. It can
be observed very strong peak intensity in 1282 cm-1, 1305-1308 cm-1, 1340 cm-1 and less peak intensity 1331
cm-1 (=diamonds).

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
12
Presser j., Monteiro M. and Maldonado a.
As done by Miyamoto (1995) in relation
to a diamonds grains in an inclusion of the
Canyon Diablo meteorite (see also Garvie &
Nemeth, 2009), we measured Raman spec-
tra of diamonds grains inclusion in the Met.
CCh. (Figure 7a and 7b) “Iron meteorite”
to obtain information on the origin of the
diamonds. The Met.CCh. Wavenumber
position of a Raman, in the “lonsdaleite/
diamond band”, ranges from 1190 to 1390
cm-1. So according the Figure 7, the rep-
resentative ve selected Raman spectra
from (Met.CCh. No. 15, 18, 22, 48 and 49)
shows an intense band between 1190-1390
cm-1 and displays the extra peaks at ~321,
~900, 1130, 1161, 1350, 1370, 1428, 1453,
1492, 1568, ~1570, 1586 and 3053 cm-1. It
is also noteworthy that between the band
1190-1390 cm-1 the peaks stand out with in-
tensity in 1244, 1282, 1307, 1341 and 1365
cm-1 and somewhat less intense the peak in
1214, 1223, 1257, 1275, 1293, 1314, 1326 and
1340-1341 cm-1; Figure 7. We should still
mention that was observed the presence
of peaks in 1492, 1546, 1568, 1570 and 1586
cm-1. More above all, it should be noted that
the presence of clear records of peaks (of
very strong intensity) 1282, 1306-1308 cm-1
and (less intensity) 1331-1336 cm-1 (the lat-
ter the diamond peaks).
In the Table 1 we compare the FWHM ob-
tained for the selected Met.CCh. diamonds
with Kimberley mine diamond, synthetic
diamond, Popigai impact diamonds (all of
them calculated through the SpectraGryph
1.2 software), Canyon Diablo iron mete-
orite impact diamonds (Miyamoto, 1998),
Ries Crater impact diamonds (Lapke et
al., 2000) and shock-produced diamonds
(Miyamoto et al., 1993). As we can see the
FWHM in the Met.CCh. diamonds are cen-
tered on peak 1282 cm-1.
ANALYSIS AND CONCLUSION
According to the results of the Raman
spectroscopy related to the ve diamonds
selected grains of Met.CCh. (Figure 7) note
that ~1265 to 1275 cm-1, as the comments of
Zaitsev (2013), is a weak band appeared in
spectra of diamond tips used for indenta-
Samples MetCCH-15 MetCCH-18 MetCCH-22 MetCCH-48 MetCCH-49 DeBeers
synthetic
Diamond-values-
kimberley mine
wavelength
[nm] 1282,5 1282,2 1282,5 1282,4 1282,5 1332,2 1337,3
FWHM[nm] 71,35 284,99 42,35 155,48 372,71 3,84 11,85
Popigai
diamond_1
Popigai
diamond_2
Popigai
diamond_3
Popigai
diamond_5
Popigai
diamond_7
Canyon
Diablo
Shock-
produced
diamonds
Riescráter
impact
diamonds
1305,2 1333 1331 1330,7 1331,1 - - ~1304–
1334
9,44 15,25 12,64 20,71 9,42 25-117 ~10-120 70-170
Samples
wavelength
[nm]
FWHM[nm]
Table 1-The “lonsdaleite/diamond band” FWHM obtained for selected Met.CCh. diamonds that are compared to
Kimberley mine diamond, synthetic diamond (both obtained from the data available in https://rruff.info/diamond/
display=default/ accessed in January 2020), Popigai impact diamonds [Murri et al., 2019], Canyon Diablo iron me-
teorite [Miyamoto et al., 1998] (see also He and Sekine, 2002), shock-produced diamonds [Miyamoto et al., 1998]
and Ries impact diamonds [Lapke et al., 2000].

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IMPACT DIAMONDS IN METAL PIECE FROM PARAGUAY
13
tions of diamonds. This feature is tentative-
ly aributed to hexagonal (6H) and rhom-
bohedral (21R) diamond polytypes. So too
a band at ~1280–1288 cm-1 was aributed
to lonsdaleite inclusions (Goryainov et al.,
2014). Also like this a (~) 1315 cm-1 band
of lonsdaleite (2H) was found to appear
in the Raman spectra of indented samples
(Goryainov et al., 2014). The spectral po-
sition of the band maximum may range
from 1311 to 1350 cm-1 and its width may
increase up to 100 cm-1. Feature that also
is describe tentatively to lonsdaleite inclu-
sions (Zaitsev, 2013).
In addition, also in relation of what is ob-
served in Met.CCh. diamonds, we can fur-
ther pinch other comments (Zaitsev,, 2013)
that indicate: the band 1313 to 1326 cm-1
is aributed to stacking faults oriented in
(111) planes (formation of lonsdaleite “hex-
agonal diamond polytypes”) and Muri et
al. (2019) arm that Raman intensity in the
1200–1350 cm-1 range can give an indication
that hexagonal layer stacking structures
are present. The 1492 cm-1, is a peak/band
observed in single-crystal diamonds under
high pressure (200 to 300 GPa) (Zaitsev,
2013).
According to calculations from the rst
principles, the Raman spectrum of lonsda-
leite consists of 3 bands: 1221 cm-1 (mode
E2g, line L2), 1280 (A1g, L1) and 1338 (E1g,
L3) (Yelisseyeva et al., 2020). In the Met.
CCh. diamonds this can be recognized be-
tween the peak in 1210-1223 cm-1; the peak
1282 cm-1 and the peak 115-1341 cm-1. So
too, the records of very strong peaks inten-
sity 1306-1308 cm-1 in Met.CCh. diamonds
should be interpreted as being due to the
presence of londsdaleite; this taking into
consideration the comments of (Goryainov
et al., 2014; Ovsyuk et al., 2019 and Murri
et al., 2019).
In Met.CCh. diamonds the peak 1214,
1293 and (1331)-1336 cm-1 they correspond
to the peaks of hchc (4H polytype) and the
peak 1223, 1275 and (1340)-1341 cm-1 they
correspond to the peaks of hh (hexagonal
diamond) both as can be interpreted from
(Jones et al., 2016; Murri et al., 2019 and
others).
Based on the comments, of the previous
paragraphs of the analysis, it can be empha-
sized that the diamond grains separated in
the Met.CCh., in principle, as lonsdaleite or
impact diamonds (lonsdaleite as described
in (Nemeth et al.,2014 and highlighted in
Ovsyuk et al., 2019)).
In the Met.CCh. impact diamonds also
is visible al Raman spectrum of meteoritic
carbón (Zaitsev,2013; Ross et al., 2011 and
Karczemska et al., 2009): ~ 321, 900, 1313,
1350, 1568, 1577, 1586 and 3053 cm-1.
The Met.CCh. impact diamonds shows
very large FWHM values of 42-373 cm-1
(Table 1). FWHM values for comparisons
is shows the registered for the Popigai im-
pact diamonds in 9 to 21 cm-1, Canyon Dia-
blo meteorite impact diamonds in 25 to 117
cm-1 shock-produced diamonds in ~10-120
cm-1 and as well as 73 to 170 cm-1 in Ries
impact diamonds (All in Table 1). The im-
pact diamond grains separated in the Met.
CCh. his high FWHM values (centered
around peak 1282 cm-1) is interpreted as
impact diamonds with signicant presence
of the lonsdaleite component.
The detailed petrological and spectro-
scopic study of ureilites showed that the
impact mechanism is dominant for the
formation of diamonds (Yelisseyeva et al.,
2020). It is assumed that impact diamonds
are formed from carbon materials present
in the rocks at the site of the meteorite fall.
High pressures and temperatures (presum-
ably, P up to 140 GPa and T up to 4000 °C)
necessary for the solid-phase graphite to
diamond transition are realized at the front
of the shock wave propagating from the
place of impact (Yelisseyeva et al., 2020).
The previous comments suggest that Met.
CCh. have experienced typically intense

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
14
Presser j., Monteiro M. and Maldonado a.
shock metamorphism, and graphite (or co-
henite, or both), taken as the original car-
bon mineral, has been partly transformed
by shock into its polymorphs diamond
and lonsdaleite; i.e., impact diamonds, that
maybe it was produced by meteorite that
was a collision in space. It is also notewor-
thy that the high FWHM values would be
an indication of a very powerful impact
would have formed the Met.CCh. impact
diamonds.
The zebra skin format which can be seen
in portions of the Met.CCh., reproduced in
the Figure 3a., reminds the melt crystalli-
zation after a shock event in the meteorites
Sikhote-Alin, Canyon Diablo and Odessa
(see Muftakhetdinova et al., 2019) and/
or reminds the quenched aggregates of
Fe-S and Fe-S-C melts and recrystallized
cohenite therein, edged by a graphite re-
action rim; the typical structure of the ex-
perimental samples at T≥1200ºC (Bataleva
et al., 2017). Preliminarily the rock chem-
istry works practiced by Dr. John Wenger
proved to be 0.13% Sulphur in the Met.
CCh. Likewise the (quenched) eutectoid
micro texture leads to suppose that the
Met.CCh. would have suered partial fu-
sion as a result of the inicted impact.
As commented at the beginning rusty is-
land of Neumann bands was seen in some
areas of the outer face of the Met.CCh.
which could also be observed petrographi-
cally in polished sections (Figure 3). A mi-
cro-textural peculiarity more properly hap-
pening in the kamacites. “Kamacite” that is
feared as the main metal phase in the Met.
CCh. (Figure 4 and 5).
This series of information seem to sup-
port the very probable meteoric character
of Met.CCh. However, the Met.CCh. char-
acterization as meteorite should be ad-
dressed in subsequent work following con-
ventional study techniques and protocols.
ACKNOWLEDGMENTS
Professor Blas Antonio Servin Bernal;
Prof. Dr. Diego Stadler; Prof. Dr. Adrian
Jones; Dr. Mara Murri; Dr. Maeo Alvaro;
Prof. Dr. Victor Kvasnytsya; Laboratorio
de Paleontología (FaCEN, UNA); Dr. John
Wenger; Pedro Benitez; Ing. Luis Fernando
Fiore and Ing. Fabrizzio Fiore, thank you
very much for your favorable contributions
to this work.
REFERENCES
Bataleva, Y.V. Palyanov, Y.N. Borzdov, Y.M. Bayu-
kov, O.A. y Zdrokov, E.V. (2017). Iron carbide
as a source of carbon for graphite and diamond
formation under lithospheric mantle P–T param-
eters. Lithos, doi:10.1016/j.lithos.2017.06.01.
Clarke, Jr. R.S. Appleman, D.E. y Ross, D.R. (2009).
An Antartic iron meteorite contains preterres-
trial impact-produced diamond and lonsdaleite.
Nature, Vol 291, 296-398.
Garvie, A. J. L. y Németh, P. (2009). The structure of
Canyon Diablo” diamonds. Lunar and Planetary
Science Conference 40, 1346.
Goryainov, S. V. Likhacheva, A. Y. Rashchenko, S.
V. Shubin, A. S. Afanas’ev, V. P. y Pokhilenko, N.
P. J. (2014). Raman identication of lonsdaleite in
Popigai Impactites. J. Raman Spectrosc. wileyon-
linelibrary.com/journal/jrs.
Grady, M.M. (2000). Catalogue of Meteorites. Cam-
bridge University Press. 689 pp.
He, H., y Sekine, T.K. (2002). Direct transformation
of cubic diamond to hexagonal diamond. Applied
Physics Leers 81, 610-612.
Jones, A. P., McMillan, P.F. Salzmann, Sh.G. Alvaro,
M. Nestola, F. Prencipe, M. Dobson, D. Hazael,
R. y Moore, M. (2016). Structural characteriza-
tion of natural diamond shocked to 60 GPa; im-
plications for Earth and planetary systems. Lithos
265, 214–221.
Karczemska, A., Jakubowski, T. y Vergas, F. (2009).
Dierent diamonds in meteorites - DaG 868 and
NWA 3140 ureilites. Journal A.M.M.E. Vol. 37, Is-
sue 2, 292-297.
Lapke, C., Smi, R.T. Kenkmann, T. y Stoer, D.
(2000). Raman microspectrometry of impact dia-

HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15 HISTORIA NATURAL Tercera Serie Volumen 10 (2) 2020/5-15
IMPACT DIAMONDS IN METAL PIECE FROM PARAGUAY
15
mond from the Ries Crater, Germany. Meteoritic
and Planetary Science Vol. 35 No 5, Supplement.
Meteoritical Bulletin Database (2013). The Meteoriti-
cal Society hp://www.lpi.usra.edu/meteor (ac-
cess in 11/2013).
Miyamoto, M. (1995). LPS XXVI, Raman Spectra of
Diamonds in the Canyon Diablo Iron Meteorite.
LPS XXVI, Provided by the NASA Astrophysics
Data System.
Miyamoto, M. (1998). Micro Raman Spectroscopy of
Diamonds in the Canyon Diablo Iron Meteorite:
Implication For The Shock Origin. Antarct. Mete-
orite Res., 11, 171-177.
Miyamoto, M. Takase, T. y Mitsuda, Y. (1993). Raman
spectra of various diamonds. Mineral. J., 16, 246-
257.
Muftakhetdinova, R. Brusnitsina, E. Yakovlev, G.
y Grokhovsky, V. (2019). Resolution and Dis-
covery, Determination of Cooling Rates by the
Structure of Spinodal Decomposition and Impact
Melting in Meteorite Substance. Resolution and
Discovery, Open Access at www.akademiai.com.
Murri, M. Smith, R.L. McColl, K. Hart, M. Alvaro, M.
Jones, A.P. Németh, P. Salzmann, Chr. G. Corà,
F. Domeneghei, M. C. Nestola, F. Sobolev, N.V.
Vishnevsky, S. A. Logvinova, A. M. y McMillan,
P. F. (2019). Quantifying hexagonal stacking in
Diamond. Scientic Reports 9, 10334.
Nemeth, P. Garvie, L.A.J. Aoki, T. Dubrovinskaia, N.
Dubrovinsky, L. y Buseck, P. (2014). Lonsdaleite
is faulted and twinned cubic diamond and does
not exist as a discrete material. Nat. Commun. 5,
5447–5452.
O, U. Begemann, F. y Löhr, H. P. (1982). Diamond-
Bearing Iron Meteorite ALHA 77287: Implica-
tions from Noble Gases. Meteoritics, Vol. 17, p.
266.
Ovsyuk, N.N. Goryainov, S.V. y Likhacheva, A.Y.
(2019). Raman scaering of impact diamonds.
Diamond and Related Materials, 91, 207–212.
Presser, J.L.B. (2019). Meteorite Blas (Cerro Chovore-
ca) initial recognition. Internal Report, Asunción
– Paraguay. 12 pp.
Prior, G. T. (1923). Catalogue of Meteorites. The British
Museum (Natural History). 196 pp.
Ross, A.J., Steele, A. Fries, M.D. Kater, L. Downes, H.
Jones, A.P. Smith, C. L. Jenniskens, P.M. Zolen-
sky, M.E. y Shaddad, M.H. (2011). MicroRaman
spectroscopy of diamond and graphite in Alma-
hata Sia and comparison with other ureilites.
Meteoritics and Planetary Science 46, Nr 3, 364–378.
Yelisseyeva, S., Gromilov V. Afanasiev, I. y Sildos,
V. K. (2020). Eect of lonsdaleite on the optical
properties of impact diamonds. Diamond and Re-
lated Materials 101, 107640.
Zaitsev, A.M. (2013). Optical properties of diamond:
A data handbook. Springer Science and Business
Media.
Recibido: 13/04/2020 - Aceptado: 04/05/2020 - Publicado: 08/09/2020

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