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Composition and paragenesis of daqingshanite from the Kamthai carbothermalite, Rajasthan, India 印度拉贾斯坦邦 Kamthai 碳热岩中的大青山石的成分和成因
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-04-01 DOI: 10.1180/mgm.2024.18
Roger H. Mitchell

Daqingshanite in the Kamthai REE deposit (India) occurs as two paragenetic types: primary granular coarse grained crystals coexisting with primary carbocernaite, baryte and bastnäsite; and as aligned micro-ovoid globules within clasts of Sr-bearing calcite. Carbocernaite forming trellis-type lamellae in some of these calcite clasts do not represent exsolution and are considered as replacement textures as they formed subsequent to daqingshanite. The origins of the textural relations of the microglobules of daqingshanite to their host Sr-calcite cannot be unambiguously determined, although an exsolution origin is not considered feasible. The textures are similar to those of ‘chalcopyrite disease’ and as such could be interpreted as replacement features formed in a low temperature carbothermal environment which should facilitate replacement. Given that daqingshanite is an early crystallising phase it is also possible that cotectic crystallisation with Sr-calcite occurred, followed by subsolidus re-equilibration with recrystallisation along specific crystallographic planes in the calcite. The Kamthai REE deposit is best described as a low temperature carbothermalite microbreccia consisting of a wide variety of clasts resulting from the autobrecciation of rocks formed during, and after, the magmatic to carbothermal transition of an undetermined parental calcite carbonatite-forming magma. Many clasts have been replaced by late stage La-enriched carbothermal fluids mixed with exogenous water during the final low-temperature stage of evolution of the deposit.

Kamthai REE 矿床(印度)中的大青山岩有两种成因类型:一种是与原生石英、重晶石和钠长石共存的原生颗粒状粗粒晶体;另一种是含硒方解石岩屑中排列整齐的微卵球状晶体。在其中一些方解石岩屑中形成的花架状层状石英并不代表外溶解,而是在大青山岩之后形成的置换纹理。大青山岩微球体与其宿主钙钛矿之间的纹理关系的起源无法明确确定,但外解起源被认为是不可行的。这些纹理与 "黄铜矿病 "的纹理相似,因此可以解释为在低温碳热环境中形成的置换特征,这种环境应有利于置换。鉴于大青山岩是一种早期结晶相,也有可能是与锰方解石发生了共晶,然后沿着方解石中特定的结晶平面发生了重结晶的次固结再平衡。Kamthai REE 矿床最适合描述为低温碳热岩微碎屑岩,由各种碎屑岩组成,这些碎屑岩是在岩浆岩向碳热岩转变期间和之后形成的,其母体方解石碳酸盐岩岩浆尚未确定。在矿床演化的最后低温阶段,许多碎屑被混合了外源水的后期富含 La 的碳热流体所取代。
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引用次数: 0
The crystal structure of charmarite – the first case of a 11 × 11 Å superstructure mesh in layered double hydroxides 查理石的晶体结构--层状双氢氧化物中首个 11 × 11 Å 超结构网格的实例
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-03-08 DOI: 10.1180/mgm.2024.11
Elena S. Zhitova, Andrey A. Zolotarev, Anatoly V. Kasatkin, Rezeda M. Sheveleva, Sergey V. Krivovichev, Igor V. Pekov, Vladimir N. Bocharov
<p>Charmarite, Mn<span>4</span>Al<span>2</span>(OH)<span>12</span>CO<span>3</span>⋅3H<span>2</span>O, is a hydrotalcite supergroup member (or layered double hydroxide, LDH) with a previously unknown crystal structure and a Mn<span>2+</span>-analogue of quintinite (commonly erroneously reported as ‘2:1 hydrotalcite’). The single-crystal X-ray diffraction (XRD) data were obtained from the specimen from Mont Saint-Hilaire, Québec, Canada and are best processed in the space group <span>P</span><span><span><span data-mathjax-type="texmath"><span>$bar{3}$</span></span><img data-mimesubtype="png" data-type="" src="https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240412100051135-0894:S0026461X24000112:S0026461X24000112_inline1.png"/></span></span>, <span>a</span> = 10.9630(4), <span>c</span> = 15.0732(5) Å and <span>V</span> = 1568.89(12) Å<span>3</span>. The crystal structure has been solved by direct methods and refined to <span>R</span><span>1</span> = 0.0750 for 3801 unique reflections with <span>F</span><span>o</span> > 2σ(<span>F</span><span>o</span>). The charmarite structure has long-range periodicity in the <span>xy</span> plane due to <span><span><span data-mathjax-type="texmath"><span>$2sqrt 3$</span></span><img data-mimesubtype="png" data-type="" src="https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240412100051135-0894:S0026461X24000112:S0026461X24000112_inline2.png"/></span></span><span>a</span>’ × <span><span><span data-mathjax-type="texmath"><span>$2sqrt 3$</span></span><img data-mimesubtype="png" data-type="" src="https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240412100051135-0894:S0026461X24000112:S0026461X24000112_inline3.png"/></span></span><span>a</span>’ scheme (or 11 × 11 Å) determined for LDHs for the first time (where <span>a</span>’ is a subcell parameter ≈ 3.2 Å). This periodicity is produced by the combination of two superstructures formed by: (1) Mn<span>2+</span> and Al<span>3+</span> ordering in the metal-hydroxide layers [Mn<span>4</span>Al<span>2</span>(OH)<span>12</span>]<span>2+</span> according to the <span><span><span data-mathjax-type="texmath"><span>$sqrt 3$</span></span><img data-mimesubtype="png" data-type="" src="https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240412100051135-0894:S0026461X24000112:S0026461X24000112_inline4.png"/></span></span><span>a</span>’ × <span><span><span data-mathjax-type="texmath"><span>$sqrt 3$</span></span><img data-mimesubtype="png" data-type="" src="https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20240412100051135-0894:S0026461X24000112:S0026461X24000112_inline5.png"/></span></span><span>a</span>’ pattern and (2) the (CO<span>3</span>)<span>2–</span> ordering according to the 2<span>a</span>’ × 2<span>a</span>’ pattern in the [CO<span>3</span>(H<span>2</span>O)<span>3</span>]<span>2–</span> interlayer sheet in order to avoid close contacts b
Charmarite(Mn4Al2(OH)12CO3⋅3H2O)是一种水滑石超群成员(或层状双氢氧化物,LDH),其晶体结构以前不为人知,是一种 Mn2+-类似物(通常被错误地报道为 "2:1 水滑石")。单晶 X 射线衍射(XRD)数据取自加拿大魁北克省圣希莱尔山(Mont Saint-Hilaire)的标本,最佳空间群为 P$bar{3}$,a = 10.9630(4),c = 15.0732(5) Å,V = 1568.89(12) Å3。该晶体结构已通过直接方法求解,并在 3801 次独特反射中精制为 R1 = 0.0750,Fo > 2σ(Fo)。由于首次为 LDHs 确定了 $2sqrt 3$a' × $2sqrt 3$a' 方案(或 11 × 11 Å)(其中 a' 为子晶胞参数 ≈ 3.2 Å),霞石结构在 xy 平面上具有长程周期性。这种周期性是由以下两种超结构组合而成的:(1) 金属氢氧化物层 [Mn4Al2(OH)12]2+ 中的 Mn2+ 和 Al3+ 按照 $sqrt 3$a' × $sqrt 3$a' 模式排序;以及 (2) [CO3(H2O)3]2- 层间薄片中的 (CO3)2- 按照 2a' × 2a' 模式排序,以避免相邻碳酸盐基团之间的紧密接触。2sqrt 3$a' × 2sqrt 3$a' 的上层结构是层间空间各组分适应金属羟基层电荷分布的一个例子。Mn2+ 和 Al3+ 阳离子的尺寸差异很大,这显然导致它们作为二价和三价阳离子的有序程度相当高,从而导致层间成分的统计有序程度较高。粉末和单晶 XRD 数据都表明,所研究的样品属于双层多晶型(2T 或 2H)的六方分支,d00n ≈ 7.57 Å。报告中还给出了查理石的拉曼光谱和波段赋值。
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引用次数: 0
Ebnerite and epiebnerite: NH4ZnPO4 dimorphs with zeolite-type frameworks from the Rowley mine, Arizona, USA Ebnerite和epiebnerite:来自美国亚利桑那州罗利矿的具有沸石型框架的 NH4ZnPO4 二形晶
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-03-08 DOI: 10.1180/mgm.2024.15
Anthony R. Kampf, Xiangping Gu, Hexiong Yang, Chi Ma, Joe Marty

Ebnerite and epiebnerite, both with the ideal formula NH4ZnPO4, are new mineral species from the Rowley mine, Maricopa County, Arizona, USA. They occur in an unusual bat-guano-related, post-mining assemblage of phases. Epiebnerite grows epitactically on ebnerite and replaces it. Ebnerite and epiebnerite are found in intimate association with alunite, halite, mimetite, newberyite, sampleite, struvite and wulfenite on hematite-rich quartz–baryte matrix. Crystals of ebnerite are colourless narrow prisms up to ~0.3 mm in length. The streak is white, lustre is vitreous, Mohs hardness is ~2, tenacity is brittle and fracture is splintery. The density is 2.78(2) g⋅cm–3. Ebnerite is optically uniaxial (–) with ω = 1.585(2) and ɛ = 1.575(2). Epiebnerite occurs as colourless prisms or blades, up to about 10 × 3 × 2 μm, in parallel growth forming ribs with serrated edges epitactic on ebnerite prisms. The streak is white, lustre is vitreous, Mohs hardness is probably ~2, tenacity is brittle. The calculated density is 2.851 g⋅cm–3. Epiebnerite is optically biaxial with all indices of refraction near 1.580. Electron microprobe analysis gave the empirical formula [(NH4)0.89K0.06]Σ0.95(Zn0.96Cu0.07)Σ1.03[(P0.97Si0.03)Σ1.00O4] for ebnerite and [(NH4)0.67K0.28]Σ0.95(Zn0.99Cu0.02)Σ1.02(P1.00O4) for epiebnerite. Ebnerite is hexagonal, P63, with a = 10.67051(16), c = 8.7140(2) Å, V = 859.25(3) Å3 and Z = 8. Epiebnerite is monoclinic, P21, with a = 8.796(16), b = 5.457(16), c = 8.960(16) Å, β = 90.34(6)°, V = 430.1(17) Å3 and Z = 4. The structures of ebnerite (R1 = 0.0372 for 1168 Io > 2σI reflections) and epiebnerite (known from synthetic monoclinic NH4ZnPO4) are zeolite-like frameworks based upon corner-sharing linkages between alternating ZnO4 and PO4 tetrahedra with channels in the frameworks hosting the NH4 groups. The two structures are topologically distinct. Ebnerite belongs to the family of ‘stuffed derivatives’ of tridymite, whereas epiebnerite possesses an ABW-type zeolite structure.

Ebnerite和epiebnerite的理想化学式均为NH4ZnPO4,是来自美国亚利桑那州马里科帕县罗利矿的新矿物物种。它们出现在一个不寻常的与蝙蝠冠有关的矿后相集合体中。表闪长岩附生在黑云母上,并取代黑云母。在富含赤铁矿的石英重晶石基质上,埃贝纳铁矿和表贝纳铁矿与明矾石、海绿石、拟镁铁矿、新贝里铁矿、闪长岩、闪长岩和乌芬铁矿紧密地结合在一起。黑云母晶体为无色窄棱柱,长度可达约 0.3 毫米。条纹为白色,光泽为玻璃光泽,莫氏硬度约为 2,韧性为脆性,断口为劈裂状。密度为 2.78(2) 克-厘米-3。辉绿岩的光学性质为单轴(-),ω = 1.585(2),ɛ = 1.575(2)。表闪长岩呈无色棱柱或叶片状,大小约为 10 × 3 × 2 μm,平行生长,在闪长岩棱柱上形成边缘呈锯齿状的外延棱纹。条纹为白色,光泽为玻璃光泽,莫氏硬度约为 ~2,韧性较脆。计算密度为 2.851 g-cm-3。表闪石具有光学双轴性,所有折射率都接近 1.580。电子显微镜分析得出的经验公式为[(NH4)0.89K0.06]Σ0.95(Zn0.96Cu0.07)Σ1.03[(P0. 97Si0.03)Σ1.03]。97Si0.03)Σ1.00O4],而表闪长岩为[(NH4)0.67K0.28]Σ0.95(Zn0.99Cu0.02)Σ1.02(P1.00O4)。埃白云母为六方晶系,P63,a = 10.67051(16),c = 8.7140(2)埃,V = 859.25(3)埃3,Z = 8;表白云母为单斜晶系,P21,a = 8.796(16),b = 5.457(16),c = 8.960(16)埃,β = 90.34(6)°,V = 430.1(17)埃3,Z = 4。埃勃来石(1168 Io > 2σI 反射的 R1 = 0.0372)和表勃来石(从合成单斜 NH4ZnPO4 中得知)的结构是基于交替 ZnO4 和 PO4 四面体之间的分角连接的沸石状框架,框架中的通道容纳了 NH4 基团。这两种结构在拓扑学上截然不同。埃勃来特属于三闪长岩的 "填充衍生物 "家族,而表勃来特则具有 ABW 型沸石结构。
{"title":"Ebnerite and epiebnerite: NH4ZnPO4 dimorphs with zeolite-type frameworks from the Rowley mine, Arizona, USA","authors":"Anthony R. Kampf, Xiangping Gu, Hexiong Yang, Chi Ma, Joe Marty","doi":"10.1180/mgm.2024.15","DOIUrl":"https://doi.org/10.1180/mgm.2024.15","url":null,"abstract":"<p>Ebnerite and epiebnerite, both with the ideal formula NH<span>4</span>ZnPO<span>4</span>, are new mineral species from the Rowley mine, Maricopa County, Arizona, USA. They occur in an unusual bat-guano-related, post-mining assemblage of phases. Epiebnerite grows epitactically on ebnerite and replaces it. Ebnerite and epiebnerite are found in intimate association with alunite, halite, mimetite, newberyite, sampleite, struvite and wulfenite on hematite-rich quartz–baryte matrix. Crystals of ebnerite are colourless narrow prisms up to ~0.3 mm in length. The streak is white, lustre is vitreous, Mohs hardness is ~2, tenacity is brittle and fracture is splintery. The density is 2.78(2) g⋅cm<span>–3</span>. Ebnerite is optically uniaxial (–) with ω = 1.585(2) and ɛ = 1.575(2). Epiebnerite occurs as colourless prisms or blades, up to about 10 × 3 × 2 μm, in parallel growth forming ribs with serrated edges epitactic on ebnerite prisms. The streak is white, lustre is vitreous, Mohs hardness is probably ~2, tenacity is brittle. The calculated density is 2.851 g⋅cm<span>–3</span>. Epiebnerite is optically biaxial with all indices of refraction near 1.580. Electron microprobe analysis gave the empirical formula [(NH<span>4</span>)<span>0.89</span>K<span>0.06</span>]<span>Σ0.95</span>(Zn<span>0.96</span>Cu<span>0.07</span>)<span>Σ1.03</span>[(P<span>0.97</span>Si<span>0.03</span>)<span>Σ1.00</span>O<span>4</span>] for ebnerite and [(NH<span>4</span>)<span>0.67</span>K<span>0.28</span>]<span>Σ0.95</span>(Zn<span>0.99</span>Cu<span>0.02</span>)<span>Σ1.02</span>(P<span>1.00</span>O<span>4</span>) for epiebnerite. Ebnerite is hexagonal, <span>P</span>6<span>3</span>, with <span>a</span> = 10.67051(16), <span>c</span> = 8.7140(2) Å, <span>V</span> = 859.25(3) Å<span>3</span> and <span>Z</span> = 8. Epiebnerite is monoclinic, <span>P</span>2<span>1</span>, with <span>a</span> = 8.796(16), <span>b</span> = 5.457(16), <span>c</span> = 8.960(16) Å, β = 90.34(6)°, <span>V</span> = 430.1(17) Å<span>3</span> and <span>Z</span> = 4. The structures of ebnerite (<span>R</span><span>1</span> = 0.0372 for 1168 <span>I</span><span>o</span> &gt; 2σ<span>I</span> reflections) and epiebnerite (known from synthetic monoclinic NH<span>4</span>ZnPO<span>4</span>) are zeolite-like frameworks based upon corner-sharing linkages between alternating ZnO<span>4</span> and PO<span>4</span> tetrahedra with channels in the frameworks hosting the NH<span>4</span> groups. The two structures are topologically distinct. Ebnerite belongs to the family of ‘stuffed derivatives’ of tridymite, whereas epiebnerite possesses an ABW-type zeolite structure.</p>","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"38 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141063109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Immobilisation of chromium in magnesium carbonate minerals 铬在碳酸镁矿物中的固定化
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-03-06 DOI: 10.1180/mgm.2023.91
Alicja M. Lacinska, Keith Bateman, Simon Chenery, Simon J Kemp, Thomas Liddy, Jeremy C Rushton, Dipankar Saha, Sven L.M. Schroeder

Hexavalent chromium (Cr6+) is a toxic carcinogenic pollutant that might be released by the mining and processing of ultramafic rocks and nickel laterites and which requires permanent removal from the contaminated biosphere. Ultramafic material can also serve as a feedstock for the sequestration of CO2 resulting from the growth of new minerals, raising the intriguing proposition of integrated sequestration of both pollutants, CO2 and chromium, into magnesium carbonates. Such a synergistic process downstream of ore recovery and mineral processing could be an elegant proposition for more sustainable utilisation and management of the Earth's resources. We have therefore carried out an experimental and microanalytical study to investigate potentially suitable carbonate minerals. Uptake of chromium in carbonate phases was determined, followed by identification of the crystalline phases and characterisation of the local structural environment around the incorporated chromium centres. The results suggest that neither nesquehonite nor hydromagnesite have the structural capacity to incorporate Cr6+ or Cr3+ significantly at room temperature. We therefore propose that further research into this technology should focus on laboratory assessments of other phases, such as layered double hyroxides, that have a natural structural capacity to uptake both chromium and CO2.

六价铬(Cr6+)是一种有毒的致癌污染物,可能会在超基性岩和红土镍矿的开采和加工过程中释放出来,需要从受污染的生物圈中永久清除。超基性岩材料还可以作为一种原料,用于封存新矿物生长过程中产生的二氧化碳,这就提出了将二氧化碳和铬这两种污染物综合封存到碳酸镁中的有趣提议。这种在矿石回收和矿物加工下游的协同过程可能是一种更可持续地利用和管理地球资源的优雅提议。因此,我们开展了一项实验和微分析研究,以调查潜在的合适碳酸盐矿物。我们测定了碳酸盐相对铬的吸收,然后鉴定了晶体相,并描述了铬中心周围的局部结构环境。结果表明,无论是内沸石还是水镁石,都不具备在室温下大量吸收 Cr6+ 或 Cr3+ 的结构能力。因此,我们建议对该技术的进一步研究应侧重于对其他相(如层状双氧化物)的实验室评估,这些相具有吸收铬和二氧化碳的天然结构能力。
{"title":"Immobilisation of chromium in magnesium carbonate minerals","authors":"Alicja M. Lacinska, Keith Bateman, Simon Chenery, Simon J Kemp, Thomas Liddy, Jeremy C Rushton, Dipankar Saha, Sven L.M. Schroeder","doi":"10.1180/mgm.2023.91","DOIUrl":"https://doi.org/10.1180/mgm.2023.91","url":null,"abstract":"<p>Hexavalent chromium (Cr<span>6+</span>) is a toxic carcinogenic pollutant that might be released by the mining and processing of ultramafic rocks and nickel laterites and which requires permanent removal from the contaminated biosphere. Ultramafic material can also serve as a feedstock for the sequestration of CO<span>2</span> resulting from the growth of new minerals, raising the intriguing proposition of integrated sequestration of both pollutants, CO<span>2</span> and chromium, into magnesium carbonates. Such a synergistic process downstream of ore recovery and mineral processing could be an elegant proposition for more sustainable utilisation and management of the Earth's resources. We have therefore carried out an experimental and microanalytical study to investigate potentially suitable carbonate minerals. Uptake of chromium in carbonate phases was determined, followed by identification of the crystalline phases and characterisation of the local structural environment around the incorporated chromium centres. The results suggest that neither nesquehonite nor hydromagnesite have the structural capacity to incorporate Cr<span>6+</span> or Cr<span>3+</span> significantly at room temperature. We therefore propose that further research into this technology should focus on laboratory assessments of other phases, such as layered double hyroxides, that have a natural structural capacity to uptake both chromium and CO<span>2</span>.</p>","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"24 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Similarities and differences among selected gemmological varieties of chalcedony: chemistry, mineralogy and microstructure 玉髓部分宝石学品种的异同:化学、矿物学和微观结构
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-02-16 DOI: 10.1180/mgm.2023.92
Sara Monico, Marco Cantaluppi, Valeria Diella, G. Diego Gatta, Ilaria Adamo, Patrizia Fumagalli, Nicoletta Marinoni

This study describes a new variety of chalcedony with a unique inhomogeneous bluish green hue, named aquaprase. It was discovered in Africa and is considered to be a valuable addition to the gem trade. A multi-methodological approach was used to examine its chemistry, mineralogy and microstructure, which were then compared to those of chrysoprase and agate, two of the most popular varieties of chalcedony. Optical microscopy revealed a complex microstructural heterogeneity in the different colour intensity areas/bands of aquaprase and agate, whereas chrysoprase exhibited a more homogeneous coexistence of micro- and cryptocrystalline quartz. High-resolution synchrotron XRD was essential for highlighting the complex assemblage of various types of α-quartz in aquaprase and agate (which differ in terms of crystal size and/or cell parameters). Micro-Raman spectroscopy revealed α-quartz and moganite in all three varieties of chalcedony and the presence of the nickel-bearing layered silicate mineral, willemseite, in chrysoprase, which is responsible for its green colouration. The chemical analysis displayed a homogeneous composition of agate, as well as high levels of nickel content in the chrysoprase variety. Aquaprase showed significant amounts (ppm by weight) of trace elements (Al, Mg, Na, K, Ca, Ti, U and Fe) characteristic of its formation environment, as well as high values of Cr, which are thought to be the cause of its bluish green colouration.

这项研究描述了一种具有独特的不均匀蓝绿色调的玉髓新品种,这种玉髓被命名为aquaprase。这种玉髓发现于非洲,被认为是宝石贸易中的珍贵新成员。研究人员采用多种方法对其化学、矿物学和微观结构进行了研究,然后将其与绿玉髓和玛瑙(两种最受欢迎的玉髓品种)的化学、矿物学和微观结构进行了比较。光学显微镜显示,水黄玉和玛瑙的不同颜色强度区域/条带具有复杂的微观结构异质性,而绿玉髓则表现出微晶和隐晶质石英共存的较均匀性。高分辨率同步辐射 XRD 对突显水黄玉和玛瑙中各种类型 α 石英的复杂组合(晶体尺寸和/或晶胞参数不同)至关重要。显微拉曼光谱显示,这三种玉髓中均含有 α-石英和莫干石,而绿玉髓中则含有含镍的层状硅酸盐矿物--钨锰铁矿,这也是绿玉髓呈现绿色的原因。化学分析显示,玛瑙的成分很均匀,绿玉髓中的镍含量也很高。水黄玉显示出其形成环境所特有的大量微量元素(Al、Mg、Na、K、Ca、Ti、U 和 Fe)(按重量计为百万分之几),以及高含量的铬,这被认为是其蓝绿色的原因。
{"title":"Similarities and differences among selected gemmological varieties of chalcedony: chemistry, mineralogy and microstructure","authors":"Sara Monico, Marco Cantaluppi, Valeria Diella, G. Diego Gatta, Ilaria Adamo, Patrizia Fumagalli, Nicoletta Marinoni","doi":"10.1180/mgm.2023.92","DOIUrl":"https://doi.org/10.1180/mgm.2023.92","url":null,"abstract":"<p>This study describes a new variety of chalcedony with a unique inhomogeneous bluish green hue, named aquaprase. It was discovered in Africa and is considered to be a valuable addition to the gem trade. A multi-methodological approach was used to examine its chemistry, mineralogy and microstructure, which were then compared to those of chrysoprase and agate, two of the most popular varieties of chalcedony. Optical microscopy revealed a complex microstructural heterogeneity in the different colour intensity areas/bands of aquaprase and agate, whereas chrysoprase exhibited a more homogeneous coexistence of micro- and cryptocrystalline quartz. High-resolution synchrotron XRD was essential for highlighting the complex assemblage of various types of α-quartz in aquaprase and agate (which differ in terms of crystal size and/or cell parameters). Micro-Raman spectroscopy revealed α-quartz and moganite in all three varieties of chalcedony and the presence of the nickel-bearing layered silicate mineral, willemseite, in chrysoprase, which is responsible for its green colouration. The chemical analysis displayed a homogeneous composition of agate, as well as high levels of nickel content in the chrysoprase variety. Aquaprase showed significant amounts (ppm by weight) of trace elements (Al, Mg, Na, K, Ca, Ti, U and Fe) characteristic of its formation environment, as well as high values of Cr, which are thought to be the cause of its bluish green colouration.</p>","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"26 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139771419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Is tapering or discontinuation of biologic treatment in patients with radiographic and nonradiographic axial spondyloarthritis reasonable? : A local cohort study. 放射学和非放射学轴性脊柱关节炎患者减量或停止生物制剂治疗是否合理? :一项地方队列研究。
3区 地球科学 Q2 MINERALOGY Pub Date : 2024-02-01 Epub Date: 2022-06-07 DOI: 10.1007/s00393-022-01226-0
Halil Harman, Nedim Kaban

Objective: We retrospectively determined factors predicting biologic treatment discontinuation or tapering in patients with axSpA.

Materials and methods: We included 63 nonradiographic axSpA (nr-axSpA) and 138 radiographic axSpA (r-axSpA) patients on biologic treatments for at least 1 year. The biologic dosing intervals were increased in patients who had been in remission for at least 6 months. In patients whose biologic dosing intervals could be increased by 100% for at least 6 months, the agents were stopped at the end of that time. In patients for whom the biologic agents were stopped or tapered, relapse was defined as a Bath Ankylosing Spondylitis Disease activity index score > 4 and a CRP level > 10 mg/L.

Results: The median duration of biologic treatment (all patients) was 2 (1-11) years. Logistic regression analysis did not identify any independent predictor of treatment discontinuation. NSAID use was the only independent predictor of tapering (p = 0.001). The time to relapse after tapering was shorter in patients with r‑axSpA than nr-axSpA (25.97 vs. 39.53 months; p = 0.05). The time to relapse in patients with r‑axSpA was considerably shorter than that in patients with nr-axSpA (5.14 vs. 13 months; p = 0.001). All r‑axSpA patients relapsed over the follow-up period; only 2 nr-axSpA patients did not relapse.

Conclusion: The most significant independent predictor of relapse was NSAID use during treatment. For axSpA patients in remission, tapering of the biologic dosing intervals is more appropriate than discontinuation.

目的我们回顾性地确定了预测轴索硬化症患者停止或减少生物制剂治疗的因素:我们纳入了 63 名接受生物制剂治疗至少 1 年的非放射性轴索硬化症(nr-axSpA)和 138 名放射性轴索硬化症(r-axSpA)患者。缓解至少 6 个月的患者的生物制剂给药间隔有所延长。如果患者的生物制剂给药间隔可以在至少 6 个月内增加 100%,则在这段时间结束时停止给药。在停用或减量使用生物制剂的患者中,巴斯强直性脊柱炎疾病活动指数大于 4 分和 CRP 水平大于 10 mg/L 即为复发:所有患者接受生物制剂治疗的中位时间为2(1-11)年。逻辑回归分析未发现任何独立的中断治疗预测因素。使用非甾体抗炎药是唯一能预测减药的独立因素(p = 0.001)。r-axSpA患者减药后复发的时间比nr-axSpA患者短(25.97个月对39.53个月;p = 0.05)。r-axSpA患者的复发时间大大短于nr-axSpA患者(5.14个月对13个月;p = 0.001)。所有r-axSpA患者在随访期间都复发了,只有2名nr-axSpA患者没有复发:结论:治疗期间使用非甾体抗炎药是最重要的复发独立预测因素。对于处于缓解期的 axSpA 患者,缩短生物制剂的给药间隔比停药更合适。
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引用次数: 0
Dmitryvarlamovite, Ti2(Fe3+Nb)O8, a new columbite-supergroup mineral related to the wolframite group Dmitryvarlamovite,Ti2(Fe3+Nb)O8,一种与黑钨矿类有关的新铌铁矿超群矿物
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-02-01 DOI: 10.1180/mgm.2023.95
Oksana V. Udoratina, Taras L. Panikorovskii, Nikita V. Chukanov, Mikhail V. Voronin, Vladimir P. Lutoev, Atali A. Agakhanov, Sergey I. Isaenko

The new columbite-supergroup mineral dmitryvarlamovite, ideally Ti2(Fe3+Nb)O8, was discovered in weathered alkaline metasomatic assemblages formed after late Riphaean sedimentary carbonate rocks of the Verkhne-Shchugorskoe deposit, Middle Timan Mts., Russia. The associated minerals are columbite-(Fe), pyrochlore-group minerals, monazite-(Ce), xenotime-(Y), baryte, pyrite, drugmanite and plumbogummite. Dmitryvarlamovite occurs as isolated anhedral equant grains up to 0.5 mm across. The colour of dmitryvarlamovite is black, the streak is black and the lustre is submetallic. The new mineral is brittle, with the mean VHN hardness of 753 kg mm–2 corresponding to the Mohs’ hardness of 6. No cleavage is observed. The fracture is conchoidal. The calculated density is 4.891 g⋅cm–3. In reflected light, dmitryvarlamovite is light grey; no pleochroism is observed. The reflectance values (Rmin, % / Rmax, % / λ, nm) are: 19.8/20.3/470, 18.3/18.9/546, 17.8/18.5/589 and 17.3/17.8/650. The chemical composition is (electron microprobe data, with iron divided into Fe2O3 and FeO based on the charge balance, wt.%): MnO 0.11, FeO 1.51, V2O3 0.89, Cr2O3 0.28, Fe2O3 19.26, TiO2 37.72, Nb2O5 40.08, total 99.85. The IR and Raman spectra indicate the absence of H-, C- and N-bearing groups. The empirical formula is (Fe2+0.08V3+0.05Cr3+0.01Fe3+0.92Ti1.79Nb1.15)Σ4.00O8. The crystal structure was determined using single-crystal X-ray diffraction data and refined to R = 0.048. Dmitryvarlamovite is orthorhombic, space group P21212, a = 4.9825(6), b = 4.6268(4), c = 5.5952(6) Å and V = 5.5952(6) Å3 (Z = 1). The structure is related to those of wolframite-group minerals but differs in the scheme of cation ordering. The crystal-chemical formula derived based on the structural data is (Ti0.57Nb0.21Fe3+0.15Fe2+0.04V0.02Cr0.01)2(Nb0.36Ti0.33Fe3+0.31)2O8. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 3.58 (40) (011), 2.911 (100) (111), 2.809 (40) (002), 2.497 (38) (020), 2.447 (29) (103), 1.7363 (32) (103) and 1.7047 (29) (220). Dmitryvarlamovite is named after Dmitry Anatol'evich Varlamov (b. 1965).

在俄罗斯中蒂曼山 Verkhne-Shchugorskoe 矿床晚期 Riphaean 沉积碳酸盐岩后形成的风化碱性偏硅酸集合体中,发现了新的铌铁矿超群矿物 dmitryvarlamovite(理想状态为 Ti2(Fe3+Nb)O8)。伴生矿物有铌铁矿(Fe)、火成岩组矿物、独居石(Ce)、氙钛铁矿(Y)、重晶石、黄铁矿、药芒硝和铂镁铁矿。德米特里瓦尔拉莫维石为孤立的等轴晶粒,直径可达 0.5 毫米。德米特里瓦尔拉莫维石的颜色为黑色,条纹为黑色,光泽为亚金属光泽。这种新矿物很脆,平均 VHN 硬度为 753 kg mm-2,莫氏硬度为 6。断口呈圆锥形。计算得出的密度为 4.891 g-cm-3。在反射光下,dmitryvarlamovite 呈浅灰色;未观察到褶皱。反射率值(Rmin, % / Rmax, % / λ, nm)为:19.8/20.3/470:19.8/20.3/470、18.3/18.9/546、17.8/18.5/589 和 17.3/17.8/650。化学成分为(电子显微探针数据,根据电荷平衡将铁分为 Fe2O3 和 FeO,重量百分比):MnO 0.11,FeO 1.51,V2O3 0.89,Cr2O3 0.28,Fe2O3 19.26,TiO2 37.72,Nb2O5 40.08,总计 99.85。红外光谱和拉曼光谱表明不含 H、C 和 N 基团。其经验公式为(Fe2+0.08V3+0.05Cr3+0.01Fe3+0.92Ti1.79Nb1.15)Σ4.00O8。晶体结构是通过单晶 X 射线衍射数据确定的,并细化为 R = 0.048。Dmitryvarlamovite 为正长晶,空间群为 P21212,a = 4.9825(6),b = 4.6268(4),c = 5.5952(6) Å,V = 5.5952(6) Å3 (Z = 1)。其结构与黑钨矿族矿物的结构有关,但在阳离子排序方案上有所不同。根据结构数据推导出的晶体化学式为 (Ti0.57Nb0.21Fe3+0.15Fe2+0.04V0.02Cr0.01)2(Nb0.36Ti0.33Fe3+0.31)2O8 。粉末 X 射线衍射图样[d, Å (I, %) (hkl)] 的最强线是3.58 (40) (011)、2.911 (100) (111)、2.809 (40) (002)、2.497 (38) (020)、2.447 (29) (103)、1.7363 (32) (103) 和 1.7047 (29) (220)。Dmitryvarlamovite 以 Dmitry Anatol'evich Varlamov(生于 1965 年)的名字命名。
{"title":"Dmitryvarlamovite, Ti2(Fe3+Nb)O8, a new columbite-supergroup mineral related to the wolframite group","authors":"Oksana V. Udoratina, Taras L. Panikorovskii, Nikita V. Chukanov, Mikhail V. Voronin, Vladimir P. Lutoev, Atali A. Agakhanov, Sergey I. Isaenko","doi":"10.1180/mgm.2023.95","DOIUrl":"https://doi.org/10.1180/mgm.2023.95","url":null,"abstract":"<p>The new columbite-supergroup mineral dmitryvarlamovite, ideally Ti<span>2</span>(Fe<span>3+</span>Nb)O<span>8</span>, was discovered in weathered alkaline metasomatic assemblages formed after late Riphaean sedimentary carbonate rocks of the Verkhne-Shchugorskoe deposit, Middle Timan Mts., Russia. The associated minerals are columbite-(Fe), pyrochlore-group minerals, monazite-(Ce), xenotime-(Y), baryte, pyrite, drugmanite and plumbogummite. Dmitryvarlamovite occurs as isolated anhedral equant grains up to 0.5 mm across. The colour of dmitryvarlamovite is black, the streak is black and the lustre is submetallic. The new mineral is brittle, with the mean VHN hardness of 753 kg mm<span>–2</span> corresponding to the Mohs’ hardness of 6. No cleavage is observed. The fracture is conchoidal. The calculated density is 4.891 g⋅cm<span>–3</span>. In reflected light, dmitryvarlamovite is light grey; no pleochroism is observed. The reflectance values (<span>R</span><span>min</span>, % / <span>R</span><span>max</span>, % / λ, nm) are: 19.8/20.3/470, 18.3/18.9/546, 17.8/18.5/589 and 17.3/17.8/650. The chemical composition is (electron microprobe data, with iron divided into Fe<span>2</span>O<span>3</span> and FeO based on the charge balance, wt.%): MnO 0.11, FeO 1.51, V<span>2</span>O<span>3</span> 0.89, Cr<span>2</span>O<span>3</span> 0.28, Fe<span>2</span>O<span>3</span> 19.26, TiO<span>2</span> 37.72, Nb<span>2</span>O<span>5</span> 40.08, total 99.85. The IR and Raman spectra indicate the absence of H-, C- and N-bearing groups. The empirical formula is (Fe<span>2+</span><span>0.08</span>V<span>3+</span><span>0.05</span>Cr<span>3+</span><span>0.01</span>Fe<span>3+</span><span>0.92</span>Ti<span>1.79</span>Nb<span>1.15</span>)<span>Σ4.00</span>O<span>8</span>. The crystal structure was determined using single-crystal X-ray diffraction data and refined to <span>R</span> = 0.048. Dmitryvarlamovite is orthorhombic, space group <span>P</span>2<span>1</span>2<span>1</span>2, <span>a</span> = 4.9825(6), <span>b</span> = 4.6268(4), <span>c</span> = 5.5952(6) Å and <span>V</span> = 5.5952(6) Å<span>3</span> (<span>Z</span> = 1). The structure is related to those of wolframite-group minerals but differs in the scheme of cation ordering. The crystal-chemical formula derived based on the structural data is (Ti<span>0.57</span>Nb<span>0.21</span>Fe<span>3+</span><span>0.15</span>Fe<span>2+</span><span>0.04</span>V<span>0.02</span>Cr<span>0.01</span>)<span>2</span>(Nb<span>0.36</span>Ti<span>0.33</span>Fe<span>3+</span><span>0.31</span>)<span>2</span>O<span>8</span>. The strongest lines of the powder X-ray diffraction pattern [<span>d</span>, Å (<span>I</span>, %) (<span>hkl</span>)] are: 3.58 (40) (011), 2.911 (100) (111), 2.809 (40) (002), 2.497 (38) (020), 2.447 (29) (103), 1.7363 (32) (103) and 1.7047 (29) (220). Dmitryvarlamovite is named after Dmitry Anatol'evich Varlamov (b. 1965).</p>","PeriodicalId":18618,"journal":{"name":"Mineralogical Magazine","volume":"97 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139771176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Arsenoústalečite, Cu12(As2Te2)Se13, a new mineral, and crystal structures of arsenoústalečite and stibioústalečite 一种新矿物砷钨锰矿,Cu12(As2Te2)Se13,以及砷钨锰矿和锑钨锰矿的晶体结构
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2024-01-10 DOI: 10.1180/mgm.2023.94
J. Sejkora, C. Biagioni, Pavel Škácha, Silvia Musetti, Daniela Mauro
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引用次数: 0
Complexity in the Au–Ag–Hg system: New information from a PGE (‘osmiridium’) concentrate at Waratah Bay, Victoria, Australia 金-银-汞系统的复杂性:来自澳大利亚维多利亚州瓦拉塔湾的一块 PGE(锇)精矿的新信息
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2023-12-13 DOI: 10.1180/mgm.2023.82
William D. Birch, Chi Ma

Au–Hg–Ag phases have been described from a variety of metallogenic orebodies and the placer deposits derived from them. In many documented placer deposits, the phases typically occur intergrown as ‘secondary’ rims to primary Au–Ag grains. The origin of these rims has been ascribed to supergene redistribution reactions during deposition or to the effects of amalgamation (i.e. use of mercury) during mining for gold. Difficulties in determining compositions and crystal structures on such a small scale have made full characterisation of these phases problematic. This paper describes a new occurrence of these phases, found by accident during investigation of a historical concentrate of ‘osmiridium’ containing a number of gold grains from beach sands at Waratah Bay, in southern Victoria, Australia. The phases occur as rims to gold grains and are intergrown on a scale of tens of micrometres or less. Application of electron microprobe analysis (EPMA) and limited electron back-scattered diffraction (EBSD) was required to characterise them. These techniques revealed the presence of the approved mineral weishanite (Au–Hg–Ag) and a phase with compositional range Au2Hg–Au3Hg surrounding primary Au–Ag (electrum) containing trace amounts of Hg. EBSD analysis showed weishanite is hexagonal P63/mmc and Au2Hg to be hexagonal P63/mcm. Comparison with published data from other localities (Philippines, British Columbia and New Zealand) suggests weishanite has a wide compositional field. Textures shown by these phases are difficult to interpret, as they might form by either supergene processes or by reaction with anthropogenic mercury used during mining. However, in the absence of any historical evidence for the use of mercury for gold mining at Waratah Bay, we consider the formation of the Au–Hg phases is most probably due to supergene alteration of primary Au–Ag alloy containing small amounts of Hg. In addition to revealing some of the reaction sequences in the development of these secondary Au–Hg–Ag rims, this paper illustrates methods by which these phases can be more fully characterised and thereby better correlated with the Au–Hg synthetic system.

从各种成矿矿体及其衍生的砂矿床中描述了金、氢、银相。在许多有记录的砂矿床中,这些相通常作为“次生”边缘与原生金银颗粒共生。这些边缘的起源被认为是沉积过程中的表生再分配反应,或者是金矿开采过程中汞化(即汞的使用)的影响。在如此小的尺度上测定成分和晶体结构的困难,使这些相的全面表征变得困难。本文描述了这些相的一个新出现,在对澳大利亚维多利亚南部Waratah湾海滩砂中含有大量金粒的“锇”的历史浓缩物进行调查时偶然发现。这些相以金颗粒的边缘形式出现,并在几十微米或更小的尺度上相互生长。需要应用电子探针分析(EPMA)和有限电子背散射衍射(EBSD)对其进行表征。这些技术结果表明,在含有微量Hg的原生Au-Ag (electroum)周围存在一组成分范围为Au2Hg - au3hg的矿物(Au-Hg-Ag)和一组成分范围为Au2Hg - au3hg的相。EBSD分析表明,魏山石为六方P63/mmc, Au2Hg为六方P63/mcm。与其他地区(菲律宾、不列颠哥伦比亚省和新西兰)已发表的资料比较表明,伟山石具有广泛的组成领域。这些相所显示的结构很难解释,因为它们可能是由表生过程形成的,也可能是与采矿过程中使用的人为汞反应形成的。然而,由于没有任何历史证据表明在Waratah Bay使用汞进行金矿开采,我们认为Au-Hg相的形成很可能是由于含有少量Hg的原生Au-Ag合金的表生蚀变。除了揭示这些次生Au-Hg - ag边缘发育过程中的一些反应顺序外,本文阐述了可以更充分地表征这些相的方法,从而更好地与Au-Hg合成体系相关联。
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引用次数: 0
Guangyuanite, Pb3Cl3(Se4+O3)(OH), a new lead-chloride-selenite mineral from the El Dragón mine, Potosí, Bolivia 来自玻利维亚波托西 El Dragón 矿的一种新的氯化铅硒矿--Guanyuanite,Pb3Cl3(Se4+O3)(OH)
IF 2.7 3区 地球科学 Q2 MINERALOGY Pub Date : 2023-12-07 DOI: 10.1180/mgm.2023.93
Hexiong Yang, Xiangping Gu, James A. Mcglasson, Ronald B. Gibbs, Robert T. Downs
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引用次数: 0
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