Abstract:A new hydrogen-containing Ca 9 (Fe 0.63 Mg 0.37 ) H 0.37 (PO 4 ) 7 phosphate with the whitlockite-type structure has been synthesized by a hydrothermal method and its structure has been studied by the single-crystal X-ray diffraction. The compound crystallizes in the trigonal space group R3c (traditional for compounds with the whitlockitetype structure) with unit-cell parameters: a = 10.3533(1) Å, c = 37.1097(4) Å. The structure has been determined using the "charge flipping" method. Ca 9 (Fe 0.63 Mg 0.37 )H 0… Show more
“…As a rule, in minerals of the merrillite subgroup the Р1A PО 4 tetrahedron is occupied (at the top of the truncate Na-prism), whereas in the whitlockite-subgroup minerals, the Р1B PО 4 tetrahedron is practically fully occupied (at the place of the missing Na-site) (Figs 5c,6). In a synthetic phase, which is very close in composition to natural deynekoite (Deyneko et al, 2014), the tetrahedron-up Р1B PО 4 is fully occupied as in whitlockite (Figs. 5e, 6).…”
Section: Structural Aspectsmentioning
confidence: 97%
“…5b). Figure 6.Comparison of deynekoite [(a), Na site lower occupied is not shown] and its synthetic analogue [(b), crystal structure data from Deyneko et al , 2014], merrillite [(c), crystal structure data from Xie et al , 2015] and whitlockite [(d), crystal structure data from Hughes et al , 2008], projection on (010). Са – light-orange balls; P2 PO 4 tetrahedron – dark blue; P3 PO 4 tetrahedron – blue; P 1A PO 4 tetrahedron – dark-green; P 1B PO 4 tetrahedron – light-green; truncate prism X O 6 – yellow; М О 6 octahedron – brown (Fe)/light-green (Mg); hydrogen – pink balls.…”
Section: Structural Aspectsmentioning
confidence: 99%
“…The mineral and its name (symbol Dnk) have been approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA), as IMA 2020-108 (Galuskin et al, 2022b). The name deynekoite is given in honour of Dr Dina V. Deyneko (born 1988) for her valuable contribution to the investigation of synthetic analogues of merrillite-group minerals (Deyneko et al, 2014). Type material was deposited in the mineralogical collection of the Fersman Mineralogical Museum, Leninskiy pr., 18/k.…”
Section: Introductionmentioning
confidence: 99%
“…The general formula of minerals of the merrillite group can be presented as follows: ( A 1 3 A 2 3 A 3 3 ) Σ9 XM ( P 1O 4 ) 3 ( P 2O 3 Ø) 3 ( P 3O3Ø), where A = Ca, Sr and Na; X = Na, Ca and vacancy (□); M = Mg, Fe 2+,3+ and Mn 2+ ; P = P; Ø = O and OH. Deynekoite is the first mineral of the merrillite group whose composition includes Fe 3+ ; it has a synthetic analogue (Lazoryak et al , 1996; Benarafaa et al , 2000; Deyneko et al , 2014).…”
Deynekoite, Ca9□Fe3+(PO4)7 (R3c, a = 10.3516(3)Å, c = 37.1599(17)Å, V = 3448.4(3)Å3 and Z = 6), a new mineral of the merrillite group was found in the contact facies of paralava of the Hatrurim Complex in the Daba-Siwaqa pyrometamorphic rock field, Jordan. The paralava, consisting of diopside, tridymite, anorthite, wollastonite and fluorapatite, is enriched in Fe-bearing phosphides and phosphates at the contact with the altered country rock. Cristobalite overgrowing tridymite has a fish-scales texture indicating that temperature of paralava could have reached 1500°C. Deynekoite with empirical formula (Ca8.90Na0.11K0.02)Σ9.03(Fe3+0.62Mg0.30Al0.05)Σ0.97P6.98V5+0.05O27.70(OH)0.30 forms transparent, light-yellow or light-brown grains up to 30–40 μm in size. Microhardness of deynekoite, VHN25 = 319(29) kg/mm2, corresponds to Mohs hardness = 4.5. Its density was calculated as 3.09 g⋅cm–3 on the basis of its empirical composition and structural data. Deynekoite is uniaxial (−), its refractive indices are ω = 1.658(3), ɛ = 1.652(3) (λ = 589 nm), and pleochroism is not observed. The formation of phosphides on the boundary of the paralava and country rock is connected with carbothermal reductive reactions and realised at temperatures above 1300°С. With decreasing temperature and increasing oxygen activity, phosphides are replaced by Fe2+-bearing phosphates. Deynekoite, which contains Fe3+ (substituting for Fe2+-phosphates) and a small amount of water, formed at temperatures of 600–800°C.
“…As a rule, in minerals of the merrillite subgroup the Р1A PО 4 tetrahedron is occupied (at the top of the truncate Na-prism), whereas in the whitlockite-subgroup minerals, the Р1B PО 4 tetrahedron is practically fully occupied (at the place of the missing Na-site) (Figs 5c,6). In a synthetic phase, which is very close in composition to natural deynekoite (Deyneko et al, 2014), the tetrahedron-up Р1B PО 4 is fully occupied as in whitlockite (Figs. 5e, 6).…”
Section: Structural Aspectsmentioning
confidence: 97%
“…5b). Figure 6.Comparison of deynekoite [(a), Na site lower occupied is not shown] and its synthetic analogue [(b), crystal structure data from Deyneko et al , 2014], merrillite [(c), crystal structure data from Xie et al , 2015] and whitlockite [(d), crystal structure data from Hughes et al , 2008], projection on (010). Са – light-orange balls; P2 PO 4 tetrahedron – dark blue; P3 PO 4 tetrahedron – blue; P 1A PO 4 tetrahedron – dark-green; P 1B PO 4 tetrahedron – light-green; truncate prism X O 6 – yellow; М О 6 octahedron – brown (Fe)/light-green (Mg); hydrogen – pink balls.…”
Section: Structural Aspectsmentioning
confidence: 99%
“…The mineral and its name (symbol Dnk) have been approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA), as IMA 2020-108 (Galuskin et al, 2022b). The name deynekoite is given in honour of Dr Dina V. Deyneko (born 1988) for her valuable contribution to the investigation of synthetic analogues of merrillite-group minerals (Deyneko et al, 2014). Type material was deposited in the mineralogical collection of the Fersman Mineralogical Museum, Leninskiy pr., 18/k.…”
Section: Introductionmentioning
confidence: 99%
“…The general formula of minerals of the merrillite group can be presented as follows: ( A 1 3 A 2 3 A 3 3 ) Σ9 XM ( P 1O 4 ) 3 ( P 2O 3 Ø) 3 ( P 3O3Ø), where A = Ca, Sr and Na; X = Na, Ca and vacancy (□); M = Mg, Fe 2+,3+ and Mn 2+ ; P = P; Ø = O and OH. Deynekoite is the first mineral of the merrillite group whose composition includes Fe 3+ ; it has a synthetic analogue (Lazoryak et al , 1996; Benarafaa et al , 2000; Deyneko et al , 2014).…”
Deynekoite, Ca9□Fe3+(PO4)7 (R3c, a = 10.3516(3)Å, c = 37.1599(17)Å, V = 3448.4(3)Å3 and Z = 6), a new mineral of the merrillite group was found in the contact facies of paralava of the Hatrurim Complex in the Daba-Siwaqa pyrometamorphic rock field, Jordan. The paralava, consisting of diopside, tridymite, anorthite, wollastonite and fluorapatite, is enriched in Fe-bearing phosphides and phosphates at the contact with the altered country rock. Cristobalite overgrowing tridymite has a fish-scales texture indicating that temperature of paralava could have reached 1500°C. Deynekoite with empirical formula (Ca8.90Na0.11K0.02)Σ9.03(Fe3+0.62Mg0.30Al0.05)Σ0.97P6.98V5+0.05O27.70(OH)0.30 forms transparent, light-yellow or light-brown grains up to 30–40 μm in size. Microhardness of deynekoite, VHN25 = 319(29) kg/mm2, corresponds to Mohs hardness = 4.5. Its density was calculated as 3.09 g⋅cm–3 on the basis of its empirical composition and structural data. Deynekoite is uniaxial (−), its refractive indices are ω = 1.658(3), ɛ = 1.652(3) (λ = 589 nm), and pleochroism is not observed. The formation of phosphides on the boundary of the paralava and country rock is connected with carbothermal reductive reactions and realised at temperatures above 1300°С. With decreasing temperature and increasing oxygen activity, phosphides are replaced by Fe2+-bearing phosphates. Deynekoite, which contains Fe3+ (substituting for Fe2+-phosphates) and a small amount of water, formed at temperatures of 600–800°C.
“…Семейство фосфатов со структурой минерала витлокита Ca 9 (Fe 0.63 Mg 0.37 )H 0.37 (PO 4 ) 7 [1] и изоструктурного ему β-Ca 3 (PO 4 ) 2 кристаллизуется в пространственных группах (пр. гр.…”
Solid solutions of phosphate with whitlockite-type Ca9-xMxDy (PO4) 7 (M = Zn2 +, Mg2 +) were obtained. The samples were studied by a complex of methods, such as X-ray phase analysis, second harmonic generation, and luminescent spectroscopy. It was established that in the series of solid solutions a change in the symmetry of the unit cell R3c-> R 3c is observed during Ca2+ -M2+ substitution, and the concentration dependence was determined. The phase transitions of the ferroelectric and antiferroelectric type and their temperature position were established by dielectric spectroscopy. The synthesized samples demonstrate intense luminescence with 350 nm excitation and the resulting radiation is in the white region of color coordinates (CIE).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
