著者

秋月 瑞彦

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.71, no.Special1, pp.105-118, 1976-07-15 (Released:2012-08-03)

参考文献数

45

著者

島 誠

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.54, no.6, pp.216-221, 1965-12-05 (Released:2008-08-07)

参考文献数

4

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Within recent years, the meteorite has become an interesting material on the geochemistry and the cosmochemistry. The Komagome iron meteorite had been one of the doubtfull meteorite in Japan. According to literatures, it fell 18th April 1926 in Tokyo and was 238g (weight). The present paper describes the following results. Ni and Co contents of this iron meteorite were about 8.0% and about 0.5% respectively. On the distribution pattern of the schreibersite, it was shown by the electron probe X-ray microanalyzer. The schreibersite was always occupied the center of the troilite phase.

著者

Ichiro SUNAGAWA Yasushi TAKAHASHI Hiroyuki IMAI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.102, no.3, pp.174-181, 2007 (Released:2007-07-03)

参考文献数

20

被引用文献数

35 39

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Alternating layers of calcite and aragonite, precipitated from mineral spring in fracture zones of serpentine mass, occur at Kashio, Oosika mura, Nagano Prefecture, Japan. Element mapping by means of Micro-area X-ray Fluorescence (MXRF) conclusively demonstrated that strontium concentrates more in aragonite layer, and not in calcite layer. Other elements including magnesium show no positive correlation with aragonite precipitation. MXRF analyses of aragonite samples from other localities and origins also indicated concentration of Sr as major impurity component, demonstrating that Sr plays essential role in metastable nucleation of aragonite in the precipitation of CaCO3 polymorphs from aqueous solution. This can be understood on the basis of modifications of surface energy term in CaCO3 nucleation in the presence of Sr. Temperature changes trigger to increase the Sr concentration in mineral spring, leading to metastable nucleation of aragonite.

著者

Tomohiro TAKEBAYASHI Yui KOUKETSU Katsuyoshi MICHIBAYASHI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.221219d, (Released:2023-07-28)

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Needle-shaped rutile inclusions occur in garnet within the quartz-eclogite at Mt. Gongen in the Sanbagawa belt, central Shikoku. They are approximately 5–25 µm along the long axis and are typically oriented along three directions, each intersecting at 120°. This indicates that the needle-shaped rutile is a lamella exsolved from the garnet. Garnet with needle-rutile inclusions is restricted to the quartz-poor domain of the quartz eclogite sample, which consist of quartz, garnet, omphacite, phengite, epidote, kyanite, and hornblende. Garnet grains with rutile lamellae show a composition of the almandine-pyrope series with 14–21 mol% grossular content. Rutile exsolution lamellae were concentrated in the range of 27–34 mol% pyrope of garnet crystals. The garnet host with rutile lamellae has a higher TiO2 content (TiO2 = 0.06–0.19 wt%) than those in rutile-free areas. These chemical compositional characteristics suggest that Ti was incorporated into the crystal structure during garnet growth and subsequently partially exsolved as rutile lamellae during the retrograde stage. Rutile lamellae in garnet have generally been regarded as indicators of ultrahigh-pressure metamorphism, but the present report from quartz-eclogite of the Sanbagawa belt, where no coesite has been found, provides evidence in a natural sample that the appearance of rutile exsolution lamellae is not necessarily under ultrahigh-pressure conditions.

著者

松原 聰 宮脇 律郎 横山 一己 清水 正明 今井 裕之

出版者

Japan Association of Mineralogical Sciences

雑誌

日本鉱物学会年会講演要旨集

巻号頁・発行日

pp.124, 2003 (Released:2004-07-26)

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東京都奥多摩町にあった白丸鉱山跡は,マンガン鉱物を含む露頭の一部が残存している.この露頭からは,過去にもいろいろな種類の鉱物,特にバリウムやストロンチウムを主成分とするケイ酸塩,炭酸塩鉱物が産出した.また,ガノフィル石のカルシウム置換体,多摩石(Matsubara et al., 2000)は前回の放流の際(1998年)に発見された.露頭は,黒色のブラウン鉱が縞状ないしパッチ状に入った全体的には赤褐色の壁で,周囲は砂岩である.通常このようなマンガン鉱体は石英に富む母岩(チャート)に伴われるが,現在見られる部分には,石英は存在しない.ケイ質放散虫もすべて曹長石化している.今回は,ブラウン鉱がパッチ状に入った部分を重点的に調査した.このような部分にも白色~淡黄褐色脈が無数に貫いている.白色脈は主に,ハイアロフェン,曹長石,方解石からできている.その他には,重晶石もふつうに見られる.やや少ないが,重土長石の場合もあり,稀にはストロンチアン石やキュムリ石の微細結晶集合も含まれる.淡黄褐色脈は,マースチュー石,多摩石,ネオトス石などからできている.やや濃い赤色の細脈や小さなパッチ状の部分はストロンチウム紅簾石である.ブラウン鉱は,ひじょうに細かい結晶の集合体で,結晶粒間には,ハイアロフェン,曹長石,マースチュー石,多摩石,ネオトス石などの極めて微細な鉱物が埋めている.薄片で観察すると,ブラウン鉱密集部の小さな空間を,屈折率が高く,多色性の明瞭な濃赤褐色の粒が満たしていることがわかる.これは,似たような色のストロンチウム紅簾石や赤鉄鉱とは明らかに異なる.薄片から一部を切り出し,ガンドルフィーカメラによってX線粉末回折値をとったところ,既知のガマガラ石(gamagarite)によく類似したパターンであることがわかった.そこで,EDSおよびWDSで化学分析をおこない,その結果からガマガラ石のFeをMnで置換したものに相当することが明らかになった.ガマガラ石は,南アフリカのGamagara Ridgeから1943年に記載されたひじょうに稀な鉱物で,理想化学組成式はBa2 (Fe3+,Mn3+)(VO4)2 (OH),単斜晶系の鉱物である.1987年にイタリアのMolinello mineから二番目の産地が発見されている.いずれもマンガン鉱床から発見されているのだが,MnよりFeの方が卓越している.白丸鉱山産のものは,実験式が(Ba1.92Na0.02Sr0.01Ca0.01)Σ1.96(Mn3+0.81Fe3+0.17Al0.01)Σ0.99[(V1.99Si0.01)O7.92](OH) 1.00(6ヶ所の平均値,水分は計算,V + Si = 2)で,明らかにMnが卓越している.格子定数は,a = 9.10(4) Å, b = 6.13(2) Å, c = 7.89(5) Å, β = 112.2(5)℃である.なお,今のところ見つかっている結晶粒は最大でも15μmであるので,単結晶解析は行っていない.このような組成のものは未知である.

著者

小林 暉子

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.81, no.10, pp.399-405, 1986-10-05 (Released:2008-08-07)

参考文献数

4

被引用文献数

3 3

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Existence of uvarovite has not been reported so far in Japan. Specimens labeled uvarovite crystals from 19 localities in Sakurai Collection were analysed by an electronprobe microanalyser, confirming some uvarovite crystals. Uvarovite and Cr-bearing andradite occur in a fine vein in aggregate of chromite or magnesiochromite. In serpentine with diopside or talc occur uvarovite, Cr-bearing andradite and Cr-bearing grossular.

著者

Mariko NAGASHIMA Yukina MORISHITA Yuji IMOTO Teruyoshi IMAOKA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.200818, (Released:2021-02-10)

被引用文献数

1

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Mineral assemblages and chemical compositions of ore minerals from the Eboshi deposit, the historical Naganobori copper mine, Yamaguchi Prefecture, Japan were investigated in order to clarify its characteristics as a skarn deposit. Some Bi–, Ag–, and Te–bearing minerals are newly identified, which contribute updating the mineralization sequence of this deposit. Samples collected from the mine dump are one massive magnetite ore, and copper ores associated with skarn gangue minerals. Skarns are categorized as clinopyroxene skarn, garnet skarn, and wollastonite skarn, and the clinopyroxene skarn is the most dominant. The major ore minerals are chalcopyrite, cobaltite, and early–stage pyrite (Py–I) and later stage pyrite (Py–II). Py–II is enriched in arsenic (~ 5.19 As wt%). The Bi–, Ag–, and Te–bearing minerals, such as native bismuth, bismuthinite, wittichenite, emplectite, tsumoite, kawazulite, hessite, and matildite are minor ore minerals. Based on the mineral assemblages and textures of the specimens examined, four ore mineralization stages were recognized; the ore mineralization stage I is characterized by the major ore minerals such as chalcopyrite, bornite, pyrrhotite, sphalerite, and Py–I. The stage II is defined by the mineralization of cobaltite, Py–II, and Bi(–Cu)–bearing sulfides such as native bismuth, bismuthinite, and wittichenite. The mineralization stage III is characterized by the Ag– and/or Te–bearing ore minerals such as matildite, kawazulite, tsumoite, and hessite. The stage IV is characterized by chalcopyrite veins cutting the main skarn masses and the host limestone. The mineralogical properties and mineralization process of the Eboshi deposit is similar to those of the skarn deposits in the Yamato mine and the Tsumo mine, and consistent with common skarn–type deposits associated with ilmenite–series granitoids in the San–yo Belt, which are characterized by the occurrence of minor Ag– and/or Te–bearing ore minerals.

著者

都城 秋穂

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.51, no.4, pp.162-172, 1964-04-05 (Released:2008-08-07)

参考文献数

34

著者

Keiko MORI Tatsuki TSUJIMORI Nelson BONIFACE

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.113, no.6, pp.316-321, 2018 (Released:2018-12-29)

参考文献数

43

被引用文献数

1 6

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We report a newly discovered assemblage of talc–kyanite in an amphibolite from the Isimani Suite of the Paleoproterozoic Usagaran Belt, central Tanzania. The amphibolite is characterized by the mineral assemblage of clinoamphibole, kyanite, talc with minor rutile, quartz, dolomite, and rare barite. The high Fe3+/(Fe3+ + Fe2+) ratio (0.48–0.80) of clinoamphibole and the presence of sulfate (barite) indicate a very–high oxidation state during metamorphism. P–T pseudosection modelling predicts that the studied talc– and kyanite–bearing amphibolites formed at high–pressure conditions (P > 1.0 GPa). Moreover, the modelling suggests formation of talc + kyanite + clinoamphibole at a highly oxidizing condition with CO2 fluid. This talc–kyanite association provides an index of high–pressure metamorphism of the Usagaran Belt and marks the oldest record of the talc–kyanite association in regional metamorphism in the Earth’s history.

著者

Tomomi HARA Tatsuki TSUJIMORI Kennet E. FLORES Jun–Ichi KIMURA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.114, no.6, pp.296-301, 2019 (Released:2020-01-22)

参考文献数

38

被引用文献数

2

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Lawsonite, jadeite, and glaucophane are iconic minerals within a Pacheco Pass metagraywacke of the Franciscan Complex, California. Those minerals and the associated quartz form the distinctive very low–temperature and high–pressure metamorphic lawsonite–jadeite–glaucophane assemblage, which is diagnostic of ‘cold’ oceanic subduction zones. In this paper, we evaluate the ability of lawsonite geochemistry to trace protoliths with in–situ trace element and Sr–Pb isotope analyses in lawsonite from the Pacheco Pass blueschist–facies metagraywacke, a classical example of trench–fill sediments in subduction zones. Initial Sr isotope ratios are relatively high (87Sr/86Sr = 0.7071–0.7074), and initial Pb isotope ratios are 206Pb/204Pb = 18.74–19.66, 207Pb/204Pb = 15.58–15.70, and 208Pb/204Pb = 38.41–39.34, which range from a MORB trend to a cluster on the EMII component. These geochemical signatures suggest the protolith of the metagraywacke mainly contained material derived from continental volcaniclastic rocks and quartzofeldspathic sediments. There is also a possibility that the protolith contains plume–related oceanic island basalt that reached or intruded into the fore–arc sedimentary sequence of California. Considering the maximum depositional age of the metagraywacke at ~ 102 Ma, the subduction of the Farallon Plate beneath the continental crust of the North American Plate might have carried alkali basalt with OIB–like isotopic signatures to the Franciscan trench. Our study proves the advantage of in–situ lawsonite Sr–Pb isotope analyses to characterize protoliths of metamorphic rocks. The results would manifest that the Sr–Pb isotopic signature of Ca–Al silicate minerals, such as lawsonite, and possibly epidote and pumpellyite, in various types of metamorphic/metasomatic rocks, would be an effective tool for investigating convergent margins.

著者

Yuzuki SHINJI Tatsuki TSUJIMORI Tatsuhiko KAWAMOTO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.114, no.6, pp.302-307, 2019 (Released:2020-01-22)

参考文献数

31

被引用文献数

2

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Late Paleozoic Yunotani eclogites in the Itoigawa–Omi area of the Hida–Gaien Belt were subjected to a blueschist–facies recrystallization and deformation after the peak eclogite–facies metamorphism. We studied fluid inclusions in quartz domains of different metamorphic stages in the retrograde eclogite. Coarse–grained quartz filling pressure shadow of porphyroblastic garnets contains transgranular fluid inclusions (Group–I) with high salinity [6.0–8.0 eq mass% NaCl, with a mean value 7.2 ± 0.6 eq mass% NaCl (n = 12)]. In contrast, transgranular fluid inclusions in later stage quartz–rich band (Group–II) in parallel to a penetrative foliation developed in matrix are characterized by lower salinity [1.1–5.8 eq mass% NaCl, with a mean value 3.4 ± 1.2 eq mass% NaCl (n = 12)]. The occurrences of fluid inclusion trails suggest that each group corresponds to the fluids entrapped prior to the blueschist–facies recrystallization and the fluids entrapped during the blueschist–facies stage, respectively. The Group–II fluid inclusions formed at blueschist–facies conditions support the idea that aqueous fluids in the subduction channel have a salinity similar to seawater (~ 3.5 eq mass% NaCl). Moreover, the Group–I fluid inclusions indicate a possibility that aqueous fluids at the eclogite–facies depth in subduction channels possess a salinity higher than seawater.

著者

Chinatsu YAMADA Tatsuki TSUJIMORI Qing CHANG Jun–Ichi KIMURA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.114, no.6, pp.290-295, 2019 (Released:2020-01-22)

参考文献数

34

被引用文献数

6

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The antigorite–grade serpentinite and Late Paleozoic high–pressure schists are main components of a serpentinite–matrix mélange in the Itoigawa–Omi area, Hida–Gaien Belt, Japan. Based on the petrologic characteristics of the high–pressure schists, the mélange is divided into two units, namely an ‘eclogitic unit’ and a ‘non–eclogitic unit’. Our preliminary in–situ boron isotope analyses of five serpentinites using a laser–ablation multiple–collector inductively–coupled–plasma mass spectrometry (LA–MC–ICPMS) found a systematic difference of boron isotopic trends among the two units in the same mélange. The ‘eclogitic unit’ serpentinites from Yunotani and Kotagi–gawa are characterized by lower δ11B value (mostly lower than +10‰), whereas the non–eclogitic unit serpentinite from Omi–gawa is higher than +10‰. Although the δ11B value of <0‰ was not measured from the eclogitic unit serpentinites, the relatively low δ11B values of <+10‰ might have recorded the signature of fluids released from deep subducted dehydrating slab. In contrast, the non–eclogitic unit serpentinite might have been affected by fluids released from shallower portion. Our new data confirmed the potential sensitivity of the boron isotope signature of serpentinites reflecting variation of high–pressure metamorphism.

著者

Daisuke NISHIO–HAMANE Takahiro TANAKA Tadashi SHINMACHI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.114, no.5, pp.252-262, 2019 (Released:2019-12-05)

参考文献数

30

被引用文献数

8

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Minakawaite, a new mineral with a RhSb composition, in association with a platinum–group mineral (PGM) placer is found from a small stream crossing the clinopyroxenite mass in serpentinite mélange of the Kurosegawa belt on the northeast side of Hikawa Dam, Haraigawa, Misato machi, Kumamoto Prefecture, Japan. Almost all PGM placer grains are based on isoferroplatinum, of which the rims are often covered by tulameenite and tetraferroplatinum. This isoferroplatinum–based grain contains small inclusions and accessories consisting mainly of osmium, erlichmanite, laurite, bowieite, cuprorhodsite, and ferhodsite–like mineral. Minakawaite occurs as the outmost surface layer with a rose gray metallic luster on the nub consisting of cuprorhodsite, ferhodsite–like mineral and/or Rh(Ge,Cu,Fe) mineral in association with an isoferroplatinum–based grain. The density of minakawaite is 10.04 g/cm3, calculated using the empirical formula and powder X–ray diffraction (XRD) data. Minakawaite has a pale gray color under the microscope in reflected light, and pleochroism is weak as a variation from pinkish pale gray to bluish pale gray. Anisotropy is moderate as reddish gray to bluish gray. Average results of ten energy dispersive X–ray spectroscopy (EDS) analyses give Rh 46.83, Sb 48.97, As 4.08 and total 99.88 wt%. The empirical formula is Rh0.998(Sb0.882As0.120)Σ1.002, based on 2 atoms per formula unit. Minakawaite is orthorhombic (Pnma) with a = 5.934(7) Å, b = 3.848(3) Å, c = 6.305(4) Å, and V = 144.0(2) Å3 (Z = 4). The seven strongest lines of minakawaite in the powder XRD pattern [d in Å(I /I0) (hkl )] are 2.860(63) (111), 2.774(35) (102), 2.250(47) (112), 2.199(100) (211), 2.162(38) (202), 1.923(49) (020), and 1.843(51) (013). Minakawaite is identical to the synthetic RhSb phase with MnP–type structure. PGM including minakawaite may occur with chromite in the magma chamber of the clinopyroxenite. Minakawaite was named in honor of Japanese mineralogist, Prof. Tetsuo Minakawa (b. 1950) of Ehime University for his outstanding contribution to descriptive mineralogy from Kyushu and Shikoku, Japan.

著者

Yoshikazu AOKI Hideo AKASAKO Kiyotaka ISHIDA

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.10, no.8, pp.385-395, 1981 (Released:2007-03-31)

参考文献数

6

被引用文献数

2 3

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Taneyamalite is triclinic, space group P1 or P-1, unit cell parameters: a=10.1882±0.0012, b=9.7544±0.0006, c=9.5674±0.0011 Å, α=90.429°±0.019°, β=71.025°±0.014°, γ=109.168°±0.007°, V=844.03±0.13 Å3, Z=1. Principal powder lines (d in Å) with relative intensities and indices are: 9.155(100) (010), 7.948(22) (-110), 4.578(15) (020), 3.614(13) (120), 3.252(37) (-130), 3.067(17) (-230), 2.774(24) (220), 2.665(18) (3-13), 2.202(21) (230), 1.696(17) (5-43), 1.686(12) (150). Wet chemical analysis gives: SiO2 40.32, TiO2 0.05, Al2O3, 2.08, Fe2O3 8.68, FeO 11.88, MnO 23.83, MgO 2.50, CaO 0.53, Na2O 1.63, K2O 0.10, H2O+ 6.99, H2O− 0.73, total 99.32%, corresponding to (Na0.91Ca0.16K0.04)Σ1.11 (Mn2+5078Mg1.07Fe2+2.85Fe3+1.87Al0.26)Σ11.83 (Si11.55 Al0.44 Ti0.01)Σ12.00(O30.63 (OH)13.37)Σ44.00 on the basis of O+OH=44. The ideal formula is (Na, Ca) (Mn2+, Mg, Fe2+, Fe3+, Al)12 (Si, Al)12 (O, OH)44, where Na and Mn2+ are the most dominant species in the respective sites. Therefore, taneyamalite is a Mn2+-dominant analogue of howieite. It is dark brown to black ni color, luster vitreous. Streak brown. Good (010) and fair (100) cleavages. Mohs’ hardness of the aggregate is 5–6. Specific gravity 3.30 (meas.), density 3.34 (calc. on unit cell data) and 3.31 (calc. on Gladstone-Dale’s law). It is optically biaxial, negative, 2V about 70°, refractive indices α=1.697, β=1.720, γ=1.732. Pleochroism and absorption are X=pale golden yellow, Y=yellowish brown, Z=dark brown; X<Y<Z. Infrared spectrum shows strong absorptions at 3525, 3420, 1029, 969, 617, 478 and 430 cm−1. These properties indicate a close relation of the mineral to howieite. The mineral occurs as aggregates of needle-like crystals in cracks or as subordinate component in metamorphosed ferruginous chert belonging to glaucophane schist facies at the Taneyama mine, Kumamoto Prefecture, Southwestern Japan.

著者

平島 崇男

出版者

Japan Association of Mineralogical Sciences

雑誌

岩石鉱物鉱床学会誌 (ISSN:00214825)

巻号頁・発行日

vol.78, no.3, pp.77-83, 1983

被引用文献数

1 15

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関東山地において,ひすい輝石+石英組合せを持つ岩石を新たに発見した。この岩石は第三紀の栃谷層と断層関係にある超塩基性岩とともに露出している。この岩石は,ひすい輝石+石英組合せが安定な変成作用(高圧条件)と,アルバイト+エジル輝石が安定な変成作用(中圧条件)の2回の温度圧力条件を記録している。

著者

Kenta YOSHIDA Tatsu KUWATANI Atsushi YASUMOTO Satoru HARAGUCHI Kenta UEKI Hikaru IWAMORI

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.171127, (Released:2018-06-07)

被引用文献数

3

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Conventional clustering algorithms such as k–means and fuzzy c–means (FCM) cluster analysis do not fully utilize the spatial distribution information of geologic samples. In this paper, we propose GEOFCM, a new clustering method for geochemical datasets with location coordinates. A spatial FCM algorithm originally constructed for image segmentation was modified for application to a sparse and unequally–spaced dataset. The proposed algorithm evaluates the membership function of each sample using neighboring samples as a weighting function. To test the proposed algorithm, a synthetic dataset was analyzed by several hyper–parameter settings. Applying this algorithm to a geochemical dataset of granitoids in the Ina–Mikawa district of the Ryoke belt shows that samples collected from the same geological unit are likely to be classified as the same cluster. Moreover, overlapping geochemical trends are classified consistently with spatial distribution, and the result is more robust against noise addition than standard FCM analysis. The proposed method is a powerful tool to use with geological datasets with location coordinates, which are becoming increasingly available, and can help find overviews of complicated multidimensional data structure.

著者

Toshio KATO Yasunori MIÚRA Nobuhide MURAKAMI

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.8, no.3, pp.184-192, 1976 (Released:2007-03-31)

参考文献数

13

被引用文献数

2 15

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Crystal structure of sugilite has been refined by the least squares method using 435 reflections measured on an automated single crystal diffractometer using MoKα radiation. The final unweighted R-factor is 0.047 for 429 reflections. The cell dimensions are: a=10.007(2), c=14.000(2)Å; space group P6⁄mcc. Sugilite is isostructural with milarite group minerals, and can be described as (K0.81Na0.19)[12] (H2O0.91Na0.64)2[9] (Fe3+1.32Na0.59Ti4+0.06Fe2+0.03)2[6] (Li2.12Al0.59Fe3+0.29)3[4]Si[4]12O30 with Z=2 by structure formula of milarite group defined by Forbes, Baur and Khan (1972). The SiO4 tetrahedra from hexagonal double rings with the composition Si12O30. These double rings are linked by Li, Al and Fe3+ atoms in tetrahedral four-coordination to form a tetrahedral frame structure. Na and H2O are located in nine-coordinated sites.

著者

Shoji HIGASHI

出版者

Japan Association of Mineralogical Sciences

雑誌

Mineralogical Journal (ISSN:05442540)

巻号頁・発行日

vol.11, no.3, pp.138-146, 1982 (Released:2007-03-31)

参考文献数

9

被引用文献数

43 46

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Mineralogical properties of tobelite, a new ammonium-dominant dioctahedral mica, found in the Ohgidani pottery stone deposit at Tobe, Ehime Prefecture, Japan, are described.This mineral, accompanied by quartz, occurs as a hydrothermal alteration product of a biotite andesite dyke. Wet chemical analysis gives a structural formula: ((NH4)0.53K0.19Na0.01    0.27)1.00 (Al1.97Ti0.00Fe3+0.03Mg0.05)2.05(Si3.17Al0.83)4.00O10(OH)2. The low interlayer charge is explained with its poorly crystallized nature. The X-ray powder diffraction pattern is very close to that of synthetic NH4Al2Si3AlO10(OH)2 by Eugster and Munoz (1966), and is satisfactorily indexed on 1M polytype cell having a=5.219Å, b=8.986Å, c=10.447Å and β=101.31°. Space group may be C2⁄m. Tobelite is characterized by its larger unit layer thickness (10.25Å) than that of potassium dioctahedral mica. This material yields an endothermic reaction and absorption bands specific to ammonium in DTA curve and infrared spectrum, respectively. Optically it is biaxial, negative, 2Vcalc.=28°. Refractive indices are α=1.555, β=1.575, γ=1.581, all±0.002.Mineralogical description is made also on tobelite from the Horo pyrophyllite deposit, Hiroshima Prefecture, Japan, which is well crystallized as compared with the Tobe material and is tentatively determined to be of 2M2 polytype.

著者

Daisuke NISHIO-HAMANE Takeshi YAJIMA Issei IKARI Yoshiya OHKI Hirofumi HORI Yoshihiro OHARA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.118, no.1, pp.230605, 2023 (Released:2023-10-12)

参考文献数

26

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Kiryuite and gunmaite were found as new minerals from Tsukubara, Kiryu City, Gunma Prefecture, Japan. Kiryuite is a Mn-rich analogue of viitaniemiite with an ideal formula of NaMnAl(PO4)F3 that mainly occurs as a white powder in cracks in triplite aggregate and occasionally forms porous plate-like aggregates up to 5 mm in size, while the grains are several micrometers in size. In most cases, the aggregates are also accompanied by small amounts of other minerals such as goyazite, gorceixite, and fluorite. Kiryuite shows white streaks with a vitreous luster, and its Mohs hardness is estimated to be 5 by analogy with viitaniemiite. The calculated density is 3.32 g·cm−3 based on the empirical formula and unit cell volume refined from powder X-ray diffraction (XRD) data. The empirical formula for kiryuite calculated on the basis of O = 4 and F + OH = 3 is Na0.97(Mn0.56Ca0.38Fe0.04Mg0.02)Σ1.00Al0.98P1.02O4(F2.29OH0.71)Σ3. Kiryuite is monoclinic (P21/m) with a = 5.425(4) Å, b = 7.128(4) Å, c = 6.817(6) Å, β = 109.41(7)°, and V = 248.7(3) Å3 (Z = 2). The parameters [d in Å (I/I0) hkl] for the six strongest lines associated with kiryuite in the powder XRD pattern are 3.123 (57) 002, 2.923 (53) 012 and 120, 2.877 (100) 121, 2.560 (27) 200, 2.263 (43) 103, and 2.155 (76) 221. Gunmaite is a new alunite-related mineral with a new structure type that has an ideal formula of (Na2Sr)Sr2Al10(PO4)4F14(OH)12. Gunmaite mainly occurs as a core in hexagonal tablet crystals that coexist with gorceixite and goyazite-like minerals. Gunmaite is colorless and transparent with a greasy to resinous luster and is non-fluorescent. As a bulk crystal including gunmaite, the Mohs hardness is 5, cleavage is perfect on {001} planes, and the tenacity is brittle. The calculated density based on the empirical formula is 3.38 g·cm−3 using the empirical formula and single-crystal XRD data. The empirical formula for gunmaite calculated on the basis of O = 16 and F + OH = 26 is (Na1.72Sr0.70Mg0.56Ca0.01)Σ2.99(Sr1.32Ba0.68)Σ2(Al9.82Mg0.18)Σ10P3.99O16F16.21(OH)9.79. Gunmaite is trigonal (R3m) with a = 6.9972(2) Å, c = 50.270(2) Å, and V = 2131.51(13) Å3 (Z = 3). The structure consists of two PO4, AlO2(OH)4, AlF6, AlOF3(OH)2, SrO6(OH)6, and NaF8 polyhedra. Kiryuite and gunmaite are products of the final stage of hydrothermal activity in association with greisenization.

著者

Daisuke NISHIO-HAMANE Takeshi YAJIMA Norimasa SHIMOBAYASHI Masayuki OHNISHI Takefumi NIWA

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

pp.230711, (Released:2023-10-25)

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Asagiite, a newly-discovered mineral having the ideal formula NiCu4(SO4)2(OH)6·6H2O, is a member of the ktenasite group, representing a Ni analogue. It occurs as a secondary mineral on smithsonite aggregates that overlie fractures in a serpentinite found in the Nakauri mine within Aichi Prefecture, Japan. Asagiite exhibits a unique pale blue-green coloration and so is named after the traditional Japanese color “asagi-iro.” Asagiite occurs as thin plate-like crystals with perfect cleavage along {001} planes. The crystal size of this mineral is typically 0.1 to 0.2 mm, although in rare cases crystals may range up to 0.5 mm in length. These crystals are vitreous, transparent and non-fluorescent and have also been shown to be brittle with a Mohs hardness of 2½. The measured and calculated densities of asagiite are 2.90(3) and 2.92 g·cm-3, respectively. This mineral is optically biaxial (-) with α = 1.577(2), β = 1.620(2) and γ = 1.631(2) together with a 2Vcalc value of 52.4°. Electron microprobe analyses determined an empirical formula (based on 2S) of (Cu3.44Ni0.76Zn0.59Co0.18Fe0.01)Σ4.98S2O7.95(OH)6.05·6H2O. Based on single crystal X-ray diffraction data, the structure is monoclinic with space group P21/c and unit cell parameters a = 5.6095(8), b = 6.1259(7), c = 23.758(3) Å, β = 95.288(4)°, V = 812.92(17) Å3 and Z = 2. Single-crystal structural determination also gives an R1 value of 0.0303. The seven most intense peaks in the powder X-ray diffraction pattern [d in Å (I/I0) hkl] were found to be 11.830 (100) 002, 5.912 (64) 004, 4.845 (55) 013, 3.920 (45) 006, 2.953 (33) 008, 2.668 (57) 202 and 2.571 (36) 123, with unit cell parameters of a = 5.614(5), b = 6.108(8), c = 23.758(18) Å, β = 95.62(7)° and V = 810.8(14) Å3.