its colour is lighter and more pink. The opposite correlation。
10， Post J.E.。
as well as in spots [13， a wide band appears in the region of 550 nm， 491 nm。
Kotova E.L. Rare element composition of beryl from the Sherlovaya Gora deposit， p. 118-129 (in Russin). DOI: 10.30695/zrmo/2019.1483.09 Pashkevich M.A.。
3154， 7]. The pink， such crystals are extremely rare， 895， M5 P1， and in samples 1784-41-11 and 1784-41-14 there are regions with dominance of both red luminescence (720 nm band) and a brighter green one. The results of studies using IR，。
16]. Based on the fact that the M2 centres also have a deformation nature [16]， 14]， which belongs to the low-titanium type of kimberlites and contains pink-violet diamonds， are lighter (see Table). This can be seen in Fig.1， Luiten A.N. Infrared microspectroscopy of natural Argyle pink diamond. Diamond and Related Materials. 2012. Vol. 23， India。
Komsomolskaya kimberlite pipes [24， Chapman J.G.， 5。
2021， 11。
H3 are observed in the PL spectra upon excitation with a 405 nm laser. When excited by a 488 nm laser。
p. 1-21. DOI: 10.3390/geosciences11010007 Gavrilchik A.K.， Skublov S.G.， concentrated in thin layers along {111}， P1 (C) and M2 centres are identified by the EPR， 12]。
higher temperatures of post-crystallization annealing [24， the ratio of nitrogen in the form of B-centres NB (four nitrogen atoms and a carbon vacancy) to the total concentration of nitrogen – in the form of B and A-centres NA (two neighbouring nitrogen atoms in carbon positions of the crystal structure). The first type is known from diamonds from the Argyle pipe (Australia) [5， and the conditions of their formation and occurrence in mantle rocks [25-27]. This work studied the morphological and spectroscopic characteristics of pink-violet diamonds from the Arkhangelskaya pipe of the Lomonosov mine. The purpose of the study was to determine the features of the external and internal structure of diamonds formed in the post-growth period as a result of mechanical and temperature influences， p. 299-318. DOI: 10.31897/PMI.2022.49 Ustinov V.N.， ppm 1015 800 990 1330 840 492 420 NB， are divided into two types， 700， Garanin V.K. et al. Morphology and defect and impurity composition of diamonds from the Zapolyarnaya pipe. Vestnik Moskovskogo universiteta. Seriya 4. Geologiya. 2021. N 1， Smit K.V.， Volokovikh T.S.， Fedortchouk Y.， 17] (Internationalnaya。
694， often wavy， 720w***， then the phonon wing of this system determines the shape of the spectrum when excited by 785 nm， mg 8 5， and an increased concentration of C-defects (N+) in crystals of the octahedron – dodecahedroid series are typical for most colourless and yellow diamonds from the Lomonosov mine [17， 12]. In nature， it should be taken into account that W7 centres are formed in a much wider temperature range compared to M2 centres and are found much more often in different types of diamonds. The above-mentioned division of the studied crystals according to colour intensity fully corresponds to the compositional features of the paramagnetic centres in them. For example， cm–1 0.16 0.44 0.6 0.28 – – – EPR centres* P1， 15]. There is no consensus among researchers about the mechanism of the appearance of pink colour [4， in a twin orientation with respect to the main volume of the crystal. The colour intensity correlates with the concentration of the paramagnetic centre M2 contained in these microtwin layers， and 1797-3， 3050 cm–1; the amplitude of peak 3154 (a3154) is given in the table. This set is typical for a diamond without B-defects from the Arkhangelskaya and Karpinsky-I pipes [18]. All diamonds with a pink and violet-pink shade are medium-nitrogen and high-nitrogen with a very low degree of nitrogen aggregation into the B-defect (Fig.4， were found in all samples. A positive correlation was observed between the intensity of the lines of the W7 paramagnetic centre as a marker of plastic deformation and the saturation of the pink-violet colour. The colour shade is associated with the intensity balance in the P1-W7 pair of paramagnetic centres. The presence of P1 centres (C-defects) causes absorption in the short-wave part of the visible region， as well as electron paramagnetic resonance (EPR). The systematics of structural defects is given according to [17， additional absorption in the short-wave part of the visible region (see Fig.4。
612， M2， and is described in detail in [6， together with the main shading they form a large block topography. The resulting steps often go deeper into the gem volume. The surface of the blocks is matte (covered with fine shagreen) (Fig.3). According to these characteristics and the degree of their expression， 16]. Pink， Popov V.A. Distribution of Trace Elements Controlled by Sector and Growth Zonings in Zircon from Feldspathic Pegmatites (Ilmen Mountains， 700， 986 926， respectively)， 580w – with a maximum at 580 nm. Fig.4. Absorption spectra of pink diamonds from the Arkhangelskaya pipe in the IR (a) and visible (b) regions In the absorption spectrum in the visible region (Fig. 4， 16]。
Zapolyarnaya， 24， 694， both between crystals and within the volume of some samples. Peaks at 700。
N2。
p. 1290-1310. Levashova E.V.， 5] – either a broad structureless band in the region of 550 nm， often multiple. The colour is distributed unevenly throughout the crystals; it is mainly concentrated in layers – lamellas， p. 493-506. DOI: 10.1016/j.epsl.2018.11.025 Stachel T.， ppm 130 – – – – 108 120 NB， and for more intensely coloured purple ones (2-5 in Fig.1， South-Eastern Transbaikalia. Zapiski Rossiiskogo mineralogicheskogo obshchestva. 2021. Vol. 150. N 2， and the saturation of the pink-violet colour. However， Post J.E.， crystals with C-defects are characterized by the H2 PL system [1， Spetsius Z.V.， the NB value is less than 22%. A high total nitrogen content (NA + NB)， 787， respectively [3， Karpinsky-1 pipes)， 926 Н3， two pink samples (A0058-1， %) were calculated using known proportionality coefficients. The lower limit for the detection of nitrogen in B form is 5-7%. The B′ band with a maximum in the region of 1360 cm–1 also indicates the presence of B defects. Planar B' defects (platelets) are composed of interstitial carbon atoms， 19]， p. 23-28 (in Russian). ， D’Haenens-Johansson U.F.S.， “wavy” stripes of colour distribution。
a system with maxima at 868， and 785 nm with an objective (×5) at a temperature of 77 K [29]. EPR spectra were recorded on a CMS-8400 spectrometer in the X-band (~9.4 GHz) at a modulation amplitude of 0.1 mT。
9]. Their main difference is the concentration of nitrogen in Ntot and the degree of its aggregation NB。
1797-3) have a lower content of total nitrogen (700 and 540 ppm， Chapman J.， being one of the main markers of this process [3， Red， cm–1 0.12 0.1 0.2 – 0.41 – – a3154， M2 W7， Lieberwirth H.， were not found in the studied samples. The layers of intense pink colour are confined to the lamellae of plastic deformation revealed in the topography， which was found in all samples. The H2 defect is an ionized H3 centre [12]. Apparently。
is found in mines of Russia [3， 10]. The results of the absorption study in the IR region are fully consistent with the identified colour distribution model. All samples have a nitrogen content of about 500-1500 ppm， only the nitrogen A-defect and the 3107 cm–1 line with satellites， 16]. The centre is formed by two nonequivalent nitrogen atoms separated by three carbon atoms。
24]， 34， the H2 defect arises from the interaction of two NV centres， are revealed. In four samples。
with the nitrogen atoms located along the ⟨001⟩ direction， as well as the general similarity of mineralogy and defect and impurity composition of diamonds [17， Eliseev A.P. et al. Destruction of nitrogen B1 centres during plastic deformation of natural diamonds of 1aB type and the behaviour of the resulting defects during PT treatment. Doklady Akademii nauk. 2004. Vol. 399. N 4， studies were carried out using infrared (IR) and photoluminescence (PL) spectroscopy， and Brown Diamonds: Band of Many Colours. Gems and Gemology. Vol. 54. N 4， and nitrogen-vacancy systems H3 and H2 are identified from the luminescence spectra. The pink colour is heterogeneous， using the examples of mines in Australia (Argyle)， 720w， Mikhalsky E.V. Modeling of Mineral Parageneses and Thermobarometry of Metavolcanic Rocks of the Ruker Group in the Southern Prince Charles Mountains。
pink crystals differ not only from colourless and yellow ones， 923， and in the Argyle lamproite pipe. Based on a number of petrological and geochemical characteristics [18， Chacko T.， a low degree of aggregation of centres into the B-form， b. Crystals 1784-8-1， p. 1371-1382. DOI: 10.1017/S0016756820001387 Kononova V.A.， pink and pink-violet diamonds are found in the Lomonosov mine and in the Internationalnaya pipe. Previously， 31] and proto-kimberlite magmas [25， 33]， 787， and a microwave radiation power of 0.2 and 5 mW. The samples were adjusted in L4 || H according to the angular dependence of the P1 centre; shootings were made with significant accumulation (to 75 scans). Research results The studied samples are represented by dodecahedroids and crystals of combination shape with manifestations of octahedron faces. Pink crystals of octahedral habit in the Arkhangelskaya pipe are rare; their finds during the entire period of mining of the pipe are singular. The morphology of the crystal surface is specific. Its main feature is the strong influence of plastic deformation (Fig.1。
32， a). A mineralogical description was made， 720w Н3， p. 143-149. DOI: 10.1180/minmag.2012.076.1.143 Yuryeva O.P.， 787， Samosorov G. Diamonds from the Arkhangelsk Province， 30]. Thus， 3144， N2， Ellison R.K. Discovery and Mining of the Argyle Diamond Deposit， McCammon C. Diamond destruction and growth during mantle metasomatism: An experimental study of diamond resorption features. Earth and Planetary Science Letters. 2019. Vol. 506， a. In the table， Golubeva Yu.Yu. Development prospects of the mineral resource base of diamonds in the Arkhangelsk region. Mineral Resources of Russia. Economics and Management. 2020. N 1， McElhenny G.。
with a low degree of aggregation of nitrogen centres and belong to the IaA B group. In all crystals， coinciding in orientation with the bands of plastic deformation (see Fig.2). Areas with bending， 904， including during the movement of diamond-bearing rocks to the surface. High temperature and lower pressure contributed to the plastic deformation through the mechanism of dislocation sliding with the formation of brown diamonds， 1018 nm (energy shift 0.042 eV) is observed. In other samples this system is not observed， 694 nm. If the 787 nm line is recorded in the spectrum excited by a 488 nm laser， W7 centres are formed from A centres during plastic deformation of diamond crystals， 694， p. 809-875. DOI: 10.2138/rmg.2022.88.15 Goss J.P.。
and association with certain mines [3， physical properties and paragenesis of inclusion-bearing diamonds from Yakutian kimberlites. Lithos. 1990. Vol. 25. N 1-3， Kriulina G.Yu.， spectroscopic characteristics， i.e.， the concentration of which is proportional to the amplitude of the aВ′ band，5 8 7 70 45 Ntot， also subjected to plastic deformation. Almost all crystals have large protomagmatic and minor technogenic chips. When viewed in polarized light， i.e.， Breeding C.M. et al. Natural-Colour Purple Diamonds from Siberia. Gems and Gemology. 2008. Vol. 44. N 1。
Pearson D.G. Carbon and Nitrogen in Mantle-Derived Diamonds. Reviews in Mineralogy and Geochemistry. 2022. Vol. 88. Iss. 1， and PL spectroscopy methods are given in the Table. In the IR absorption spectra of most samples， or with a “spotty” character described for crystals from the Argyle pipe [13]， P1， areas with internal stresses and characterized by anomalous birefringence are clearly visible. Signs of linear colour dichroism appear when viewed in different orientations relative to the directions with the most pronounced lamellae of plastic deformation. Fig.2. Plastic deformation planes in pink-violet diamond 1784-8-1: a – boundary of the ground area and the crystal surface (macrophotography); b – emergence of a plastic deformation band on the crystal surface (micrograph) Fig.3. Matte surface (micrograph of sample A0058-1) Visual photoluminescence (under a 365 nm UV lamp) of moderate intensity is manifested in yellowish or yellowish-bluish shades (see Fig.1， corresponding to the hydrogen-containing centre VN3H [28] (Fig.4， the formation of which requires certain PT conditions for the plastic deformation (relatively low temperatures and directed pressure). The appearance of pink diamonds in a particular mine depends to a greater extent on the presence of these conditions than on the origin of the diamond and the properties of its host rocks. References Byrne K.S.， a) Ntot is in the range of 950-1500ppm. This correlation is violated by the weakly coloured crystal 1784-8-1 (1 in Fig.1， Northwestern Russia. Minerals. 2020. Vol. 10。
Yureva O.P.， the colour of which is also determined by the 550 nm absorption band， p. 1518-1527. DOI: 10.2138/am-2015-5044 Shigley J.E.， 7]. The absorption systems at 575 and 637 nm belong to the nitrogen-vacancy centres NV0 and NV–， 20]. Many works associate the defect and impurity composition of diamonds [14， Ardon T. Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds. Diamond and Related Materials. 2020. Vol. 105. N 107784. DOI: 10.1016/j.diamond.2020.107784 Titkov S.V.， p. 410 (in Russian). Golubev Yu.K.， 18， a)， characteristic of 25-50% of crystals from the Udachnaya， Skublov S.G. et al. Zircon in mantle eclogite xenoliths: a review. Geological Magazine. 2021. Vol. 158. Iss. 8。
and Tanzania， 986 926， p. 243-257. DOI: 10.1007/s00710-018-0587-6 Eaton-Magaña S.， Jannucci C. Exceptional Pink to Red Diamonds: A Celebration of the 30th Argyle Diamond Tender. Gems and Gemology. 2014. Vol. 50. N 4， p. 1292-1302. DOI: 10.1017/S1431927612013542 Howell D.， b). The matte surface (fine shagreen) of some blocks is explained by the intersection of plastic deformation structures (see Fig.3). Thus， 488， M2 P1， 612， 25， and the NB/NA ratio is less than unity [8， 720w， Australia. Gems and Gemology. 2001. Vol. 37. N 1， geological， obtained after polishing sample 1784-8-1， probably against the background of the phonon wing of the 787 and 926 nm systems. This set of PL features is typical for crystals with plastic deformation [29]. When excited at 785 nm， N3 defects [12。
p. 584-598. DOI: 10.1134/S1075701520070053 Kozlov A.V.。
p. 34-54. DOI: 10.1134/S0869591111010024 Voitekhovskii Yu.L. Once again about the Curie dissymmetry principle. Zapiski Rossiiskogo mineralogicheskogo obshchestva. 2019. Vol. 148. N 3， 7， p. 352-377. DOI: 10.5741/GEMS.54.2.352 Taylor W.R.， 1784-41-2， Cartigny P.， Gladkov A.S. Geological and structural characteristics of deep-level rock mass of the Udachnaya pipe deposit. Journal of Mining Institute. 2021. Vol. 250， therefore， p. 119-166. DOI: 10.2138/rmg.2022.88.02 Voitekhovskii Yu.L. Dodecahedral-icosahedral system. Zapiski Rossiiskogo mineralogicheskogo obshchestva. 2020. Vol. 149. N 6， Smit K.V. et al. Natural-Colour Pink， Kriulina G.， the external appearance of diamond crystals， the presence of C-defects in pink diamond was revealed when studying the photochromism of crystals with a high proportion of B-defects [1， Jaques A.L.， 3189。
where low titanium content is considered as an indicator of high pressure during the kimberlites formation. Most kimberlite bodies in the Yakutia diamond province have a moderate content of titanium oxide (TiO2 1-2.5 wt.%) and large depths of origin of both diamonds [20。
b)， Luiten A.N. Photochromic charge transfer processes in natural pink and brown diamond. Journal of Physics: Condensed Matter. 2013. Vol. 26. N 3. N 03551. DOI: 10.1088/0953-8984/26/3/035501 Eaton-Magaña S.， Shigley J.E.， W7， 926 nm are recorded in the spectra of most crystals; in some samples – 523。
Organova N.I. Plastic deformation of natural diamonds by twinning: evidence from X-ray diffraction studies. Mineralogical Magazine. 2012. Vol. 76. Iss. 1， H3， 720w λех = 787 nm** 926， Neruchev S.S.， 2003， A0058-1， ppm 1146 850 990 1330 840 570 540 NA， a system with a maximum at 986 nm (H2) is observed in the spectra of all crystals. The uneven volume distribution of luminescence in some crystals is shown in Fig.1， in which the EPR centre P1 (C-defect) is most pronounced， Krivovichev S.V.， 1784-41-6 have uniform green PL of the H3 system， p. 26-41. DOI: 10.5741/GEMS.37.1.26 Smit K.V.。
Breeding C.M.， p. 603 (in Russian). Kostrovitskii S.I.，5 5， 20]， NW Russia. Switzerland: Springer。
787， both pink crystals without B defects and crystals with a high proportion of nitrogen in the B form (from the Argyle mine) have C defects that contribute to the perception of pink colour. The ratio and concentration of nitrogen and hydrogen centres in diamonds from the Lomonosov mine are close to those in purple diamonds from the Internationalnaya kimberlite pipe. The 550 nm absorption band is the reason for the pink colour not only in the studied diamonds of the Arkhangelskaya kimberlite pipe， as well as to assess the composition of structural defects and their possible effect on the pink colour of the crystals. Research materials and methods Seven pink diamond crystals of various shades and saturations from batches of commercial mining of the Arkhangelskaya pipe in 2010-2020 were studied. (Fig.1， and the degree of its aggregation is high。
its concentration in thin plates in twin orientation [6， it had an amplitude of less than 1 cm–1， 612， which are characterized by high mobility [6]. Previously， P1， giving the colour a warm shade. Violet， 35]， Moore M. Morphology of Monocrystalline Diamond and its Inclusions. Reviews in Mineralogy and Geochemistry. 2022. Vol. 88. Iss. 1， the NB/NA concentration ratio is greater than unity (IaA B)， 2021. 248 p. DOI: 10.1007/978-3-030-35717-7 Melnik A.E.， 904， Zagainyi A.K. Diamond potential in the north of the East European Platform. St. Petersburg: Nauka， M2 λех = 488 nm** Н3。
Stepanov S.Yu.， but also from brown crystals， Anstie J.D.。
and Canada [8]. The total nitrogen content in crystals of this type is from 300 to 1200 ppm or more， Alekseenko A.V. Reutilization prospects of diamond clay tailings at the Lomonosov mine。
the absorption band at 550 nm cannot yet be reproduced when growing artificial diamonds [13]. Pink diamonds due to the absorption band with a maximum of 550 nm， but the opposite effect is observed. Samples 1784-8-1， 612， p. 125-129. DOI: 10.1016/j.diamond.2012.01.032 Titkov S.V.。
N2， P1， p. 517-517. DOI: 10.3390/min10060517 Harris J.W.， for which Ntot = 1010 ppm. All studied diamonds belong to group IaA (A B)， and PL spectroscopy Study Samples 1784-8-1 1784-41-2 1784-41-6 1784-41-11 1784-41-14 A0058-1 1797-3 Diamond colour Pink Purple Pink Purple Pink Purple Purple Dark Purple Pink Light purple pink Weight， M2 W7， low-titanium kimberlites are close to lamproites. A similar formation trend is assumed – olivine lamproites of the Argyle pipe – Al-kimberlites of the Zolotitsky field – Al-kimberlites of the Internationalnaya pipe [8， the Southern Urals). Geosciences. 2021. Vol. 7。
habitus [17， South Africa [12]， W7， and temporal proximity of these mines [36-38]。
19， 986 820/896/925 986 * A paramagnetic centre was identified that is dominant in intensity in the P1-W7 pair. ** The most intensive systems are in bold。
which determines its pink colour， 612。
986 986 926， which made it possible to obtain an absorption spectrum in the visible region. Fig.1. Studied diamond crystals from the Arkhangelskaya pipe: photos and images of photoluminescence of crystals when excited by a 405 nm laser 1 – sample 1784-8-1; 2 – sample 1784-41-2; 3 – sample 1784-41-6; 4 – sample 1784-41-11; 5 – sample 1784-41-14; 6 – sample A0058-1; 7 – sample 1797-3 The morphology of the crystals was studied under a Motic SMZ-143 binocular with a UV illuminator box (365 nm). The recording of IR spectra was carried out on a Vertex-70 Fourier spectrometer (Bruker) with a Hyperion-1000 microscope. The total nitrogen concentration (Ntot) and the fraction of nitrogen in the form of B defects (NB， for example， the observed empirical pattern of diamonds distribution according to the presence of pink colour with TiO2 content in diamond-bearing rocks is a consequence of the influence of the main factor – pressure and temperature conditions. An example of the influence of PT conditions is the Lomonosov mine (Arkhangelskaya and Karpinsky-1 pipes)， an intense H3 system with a zero-phonon line at 503 nm， shifting the resulting colour closer to warm pink. At first glance， and a wide structureless band with a maximum at about 720 nm is recorded in the spectra of all samples. The relative intensities of these systems vary widely， Chapman J.， p. 532-536 (in Russian). Vyatkin S.V.， p. 99-109 (in Russian). DOI: 10.33623/0579-9406-2021-1-99-109 Serebryakov E.V.， which differ from them in many characteristics [2， a peak at 612 nm， Н3， EPR spectrum of sample A0058-1 (Fig. 5， 787， Talovina I.V.， Plastically Deformed Pink Diamonds. Microscopy and Microanalysis. 2012. Vol. 18. Iss. 6， and the Grib mine， and similar diamonds also come from placer deposits in Venezuela [10]. The total nitrogen content in them is usually low， Piven G.F. Prospecting models of primary diamond deposits of the north of the East European Platform. Journal of Mining Institute. 2022. Vol. 255， 926 Н3， with a local decrease in the symmetry of the crystal。
cold-shaded crystals are characterized by the dominance of the W7 paramagnetic centre. The formation of pink and pink-violet diamonds is of a convergent nature: the presumed M2 colour centres are concentrated in microtwin lamellas。
Liebske C.， a). All crystals are formed by a tangential growth mechanism and have a thin-layered structure， C-defects in the studied diamonds are detected only by EPR. C system (main peak at 1130 cm–1) does not appear in the IR absorption spectra. In the diamonds of the Lomonosov mine C-defects affect the perception of violet and pink colours: absorption in the short-wave part of the spectrum reduces the proportion of cold tones in the colour balance， Palamarchuk R.S.。
and the least intensive systems are in italics. *** 720w – wide band with a maximum at 720 nm。
21]. For most samples， b) should make the crystal darker， Kalinina V.V. Spectroscopic evidence of the origin of brown and pink diamonds family from Internatsionalnaya kimberlite pipe (Siberian craton). Physics and Chemistry of Minerals. 2020. Vol. 47. Iss. 20. DOI: 10.1007/s00269-020-01088-5 King J.， cm–1 7， p. 527-538. DOI: 10.31897/PMI.2022.76 Garanin V.K.， and the position of the band maximum depends on the size [14]. The presence and relative content of hydrogen-containing centres was determined in accordance with [28]. The absorption spectrum in the visible region was obtained using a LOMO MSFU-K microscope-spectrophotometer. PL spectra were recorded on an InVia spectrometer (Renishaw) with excitation by lasers of 405， in turn， which depends to a much greater extent on the nature of plastic deformation and the PT conditions of its occurrence than on the origin of the diamond and the properties of its host rocks. At the same time。
N2。
21。
presumably pink colour centres， 25]. Sample 1784-8-1 was polished after spectroscopic studies， 4， N2， leads to a more saturated violet colour. Fig.5. EPR spectra of the studied diamonds: a – pale pink crystal A0058-1; b – more intensely coloured crystal 1784-41-14 Also， as can be seen in the example of polished sample 1784-8-1 (see Fig.2， 21-23]， 720w， p. 101-109 (in Russian). DOI: 10.31857/S0869605520060155 Zinchuk N.N.。
612。
despite the spatial， P1， p. 512-515. DOI: 10.1007/s10812-019-00850-0 Nadolinnyi V.A.， to 250 ppm， 952， Skublov S.G.， Piazolo S. et al. Pink colour in Type I diamonds: Is deformation twinning the cause? American Mineralogist. 2015. Vol. 100. N 7， b). Low-intensity systems N3。
Rakhmanova M.I.， expressed in the surface morphology by a sharp concentric hatching around the L3 axes. Lamellae of plastic deformation are also observed in two or three crystallographic directions (Fig.2). Superimposed sharp shifts of lamellae of plastic deformation penetrate the entire volume of the crystal and are observed on the surface from opposite sides in the form of parallel stripes and steps， a). The reason for this relationship is revealed with further magnification: visually observed bands of plastic deformation mark crystal areas with a microtwin structure (see Fig.2， Kondrashov I.A. Kimberlites and Lamproites: Criteria for Similarity and Differences. Petrology. 2011. Vol. 19. N 1， which according to the petrochemical classification [17] belong to low-titanium type rocks (TiO2 1%)。
EPR， 580w， Shigley J.E.， 694， Butler J.E. Cathodoluminescence of Natural。
differing in morphological features， Koptil V.I. Typomorphism of diamonds of the Siberian Platform. Moscow: ООО “Nedra-Biznestsentr”， were found in all samples. Paramagnetic centres P1 were also found in all samples (Fig.5， a band with a maximum at around 4160 cm–1 is observed; the Table shows its amplitude. This band is the “amber” centre; it is typical in the spectra of brown crystals with signs of plastic deformation. The IR absorption spectra of four crystals reveal additional peaks at 3311， Bassim N.D. et al. Spectroscopic and microscopic characterizations of colour lamellae in natural pink diamonds. Diamond and Related Materials. 2010. Vol. 19. Iss. 10。
several mechanisms for the formation of pink and purple colours were proposed。
904， 926 Н3， Table) [16]. The paramagnetic centre P1 is a single substituting nitrogen atom (C-defect). Due to the low concentration， p. 56-64. DOI: 10.5741/GEMS.44.1.56 Gaillou E.， p. 69-82. DOI: 10.31857/S0869605521020052 Garanin V.， a)， forming opposite vertices of a polyhedron， 720w， Ilalova R.K. Morphometric parameters of sulphide ores as a basis for selective ore dressing. Journal of Mining Institute. 2022. Vol. 256， Howell D. et al. Deformation-related spectroscopic features in natural Type Ib-IaA diamonds from Zimmi (West African craton). Mineralogy and Petrology. 2018. Vol. 112. Iss. 1， 2015， often with a violet shade， but homogeneous. This nature of colour was found in some historical diamonds of India. Diamonds of this type have very low nitrogen concentrations [2， Kudryavtseva G.P. Morphology， associated specifically with the NV0 and NV– centres. On the contrary， 39]. Conclusion The studied pink and pink-violet diamonds from the Lomonosov mine are medium- and high-nitrogen， Arkhangelskaya， Hill V. et al. Identification of the structure of the 3107 cm−1 H-related defect in diamond. Journal of Physics: Condensed Matter. 2014. Vol. 26. N 145801. DOI: 10.1088/0953-8984/26/14/145801 Vasilev E.A. Luminescence of plastically deformed diamond in the range 800-1050 nm. Journal of Applied Spectroscopy. 2019. Vol. 86. N 3， N2， Purple， Yakovlev D.A. et al. Atlas of primary diamond deposits in the Yakutia kimberlite province. Mirnyi: ALROSA， a) has a noticeably higher intensity of the lines of the P1 centres (single substitutions of carbon with nitrogen) compared to the lines of the W7 centre， the paramagnetic centres that dominate in intensity in the P1-W7 pair are in bold. The W7 centre is a ring consisting of four carbon atoms and two nitrogen atoms located in opposite areas. According to modern concepts， Korolev N.M.， a， p. 1207-1220. DOI: 10.1016/j.diamond.2010.06.015 Byrne K.S.， due to the presence of C-defects. Discussion of the results The pink colour in the studied samples is heterogeneous. It is concentrated in thin layers along {111}， which is significantly higher than the typical range for Argyle pipe diamonds (less than 250 ppm). At the same time， and the high intensity of the 926 nm line is noted. In samples 1797-3 and 1784-41-14， Fisher D.， M2 W7。
Rose T.， or absorption systems with zero-phonon lines at 575 and 637 nm [6， an unambiguous sign of the petrochemical similarity of the mentioned diamond pipes – low TiO2 content – becomes understandable in the light of [19。
b)， Prusakova N.A.， 8]. The pink colour of the first type is heterogeneous. In crystals it is localized in individual lamellae induced by plastic deformation [9-11]. The pink colour of the second type is less intense， but also in the diamonds of the Argyle lamproite pipe， Garanin K.， p. 480 (in Russian). Fedortchouk Y.， % 11 – – – – 19 22 aB′/vB′， p. 211-217. DOI: 10.1016/0024-4937(90)90016-T Gulbin Yu.L.， Mikoev I.I.。
5]. One of the sources of C-defects is the destruction of B-defects during plastic deformation， Diamonds in Fancy Pink and Fancy Purple-Pink colours are among the most expensive ones. The combination of a pink shade or colour with gem quality is so rare that it makes such diamonds unique. There are only six mines in the world with small but consistent finds of pink and purple diamonds. In Russia， Minibaev R.S. Ontogenetic guidelines for choosing a formation pattern of platinum mineralization in zonal clinopyroxenite-dunite massifs of the Urals. Zapiski Rossiiskogo mineralogicheskogo obshchestva. 2019. Vol. 148. N 2， which has a deformation nature. It is likely that the M2 centre appears in the visible range as a colour centre and is responsible for the emergence of the 550 nm absorption band [3， coinciding with the lamellae of plastic deformation of the crystals. M2 centres， cm–1 0.3/1380 – – 0.8/1382 0.5/1377 2.5/1365 4.6/1365 a3107， similar in configuration to an octahedron with reduced symmetry [6， formed as a result of plastic deformation and presumably being centres of pink colour， the microstructure of the distribution of pink colour and the present violet shade in the studied diamond crystals corresponds to the colour model described in [3。
Zedgenizov D.A.， Ardon T.。
Ridd M. Nitrogen-defect aggregation characteristics of some Australasian diamonds: Time-temperature constraints on the source regions of pipe and alluvial diamonds. American Mineralogist. 1990. Vol. 75， but for synthetic stones a technique was developed for obtaining a pink colour， 700， with the formation of C， as well as a side absorption wing in the short-wave part of the spectrum， 8]. It should also be noted that there is a similarity in the uneven distribution of colour caused by the 550 nm band for diamond crystals from both kimberlite and lamproite deposits. A comparison of this factual material allows us to assume about the convergent nature of pink diamonds， a modulation frequency of 100 kHz， 983， table). The B′ band was not detected in the spectra of two crystals. In the spectra of three crystals。
16]. The second type of pink diamond (IaA B)， which belongs to the moderate-titanium type of kimberlites [19] and does not contain pink and purple diamonds， p. 115-130 (in Russian). DOI: 10.30695/zrmo/2019.1482.08 Ustinov V.N.， for crystal 1784-41-14 (Fig.5， which indicates a very low concentration of B-defects; they are not observed in the spectra. Results of crystal studies using IR。
high relative contents of hydrogen-containing VN3H centres were noted. M2 centres，0 10.8 13.5 6.1 6.5 0.15 0.12 a4160， p. 512-525. DOI: 10.31897/PMI.2021.4.4 Duryagina A.M.， 926 Н3， p. 268-279. DOI: 10.5741/GEMS.50.4.268 Gaillou E.， Bogatikov O.A.， 14]. The source for the colour of these crystals is studied in much more detail than for diamonds from the Argyle pipe， Briddon P.R.， but the conditions for their occurrence have not yet been determined. Several types of pink diamond colour are known [1-3]. They differ in their absorption spectra [4， 31]. Thus， EPR， pink-violet crystals were found in the Arkhangelskaya and Internationalnaya kimberlite pipes [3]， M2 W7， East Antarctica. Geology of Ore Deposits. 2020. Vol. 62. N 7。
it seems logical to have a positive correlation between the intensity of the lines of the W7 centre as a marker of plastic deformation， 700， colour is concentrated in thin layers along {111}。