Encyclopedia of Japanese Minerals (Go to Intro Page)
by Alfredo Petrov
Minerals Starting with "G"
GADOLINITE-(Y) (gadorin-seki; ittoro-gadorin-seki)
Fukushima: In rare-earth pegmatite at Suishohyama as dark green masses to 3cm. Also at Fusamata.
Mie: Very dark brown, lustrous crystals to 2cm in Yokkaichi city. Dark green crystals at the Naegi mine. Greenish black, dull subhedral crystals to over 2cm at Ishigure (Ishigureminami) (probably = one of the previous 2 localities). Also at Suizawa (= one of 1st 2 locs.???).
Yamanashi: Takehinata, as dark green crystals.
GAHNITE (aen-supineru)
Fukuoka: Nagatare.
Fukushima: Ishikawa district. In a pegmatite in Nogisawa-mura. Also reported from Kisawa. (same places???????????)
Hiroshima: Greenish brown, bipyramidal crystals to 3 mm size at Hayashi, on Ikuchi island, associated with a pneumatolytic copper deposit in a greisen vein crossing a granite quarry.
Nara: Bodaiyama.
GALAXITE (mangan-supineru)
Shiga: Tiny grains are a major component of alleghanyite-galaxite-hausmannite ore, and significant minor component of rhodochrosite-sonolite-manganosite ore, at the Ioi mine, where several "veins" of metamorphosed Mn ore are emplaced along bedding faults in Paleozoic chert about 3km west of a granitic batholith. First recognized in 1949, as the 3rd world locality for galaxite, some of it much purer than the type locality material: (Mn 0.830 Fe'' 0.165 Zn 0.013) (Al 1.96 Fe''' 0.035) O4. Two varieties here differ in ferric iron content (replacing aluminium): Low-Fe''', nonmagnetic galaxite is light brown in both reflected and transmitted light; High-Fe''', magnetic galaxite, close to equimolar galaxite-jacobsite, are dark chocolate-brown in reflected light, reddish brown in transmitted light. Easily extracted from its matrix, because it is not affected by hot concentrated HCl. RI 1.842<1.870; D 4.05<4.25.
Tochigi: Galaxite occurs with jimboite in contact metasomatic banded rhodochrosite ore near a granite intrusion at the Kaso mine. The "chocolate ore" here is rich in galaxite with jacobsite, sometimes also wiserite. Mg-Fe''-bearing galaxite from the Ou'ashi mine, the 2nd locality in the world for this species, was originally described in 1936 as "PICROGALAXITE", but the author himself later withdrew the name in favor of plain galaxite. Analysis shows (as wt% oxides) Si 0.33, Ti 0.23, Al 58.13, Fe'' 10.16, Mn'' 25.50, MgO 5.92, ig. loss 0.52. Ignoring Si-Ti, this corresponds to (Mn'' 0.60, Mg 0.25, Fe'' 0.24) Al 1.91 O 4 (a small amount of the Mn or Fe presumably being really trivalent and substituting for Al). Yellow to yellowish brown crystals, with the o(111) octahedron face dominating, sometimes with spinel-law twinning, are associated with manganosite, tephroite, alabandite, rhodochrosite, in metasedimentary Mn ore.
GALENA (hoh-en-koh)
Akita: At the Daira mine, cuboctahedral galena crystals to 10cm on an edge (normally less than 5cm), with cube and octahedron faces roughly equally developed, frequently thinly encrusted with tiny quartz and rhombohedral calcite xls, associated with chalcopyrite and pyrite on black sphalerite in an epithermal quartz vein. Perfect individual crystals rare - more commonly as crystal aggregates. From the Osarizawa copper-lead-zinc mine come cubic xls to 3 cm with corners truncated by octahedron faces, associated with pyrite, chalcopyrite and calcite in cavities in an epithermal quartz vein. At the Ani mine, as excellent cubes modified by tiny octahedron faces, and as sharp 8mm cuboctahedrons, with drusy quartz, sphalerite xls and chalcopyrite xls in cavities in epithermal pyrite-sphalerite-bearing quartz vein. At the Arakawa mine, cubic xls to 5mm are associated with sphalerite and chlorite in cavities in an epithermal quartz vein. In the Hatsuishi orebody at this mine, cubic crystals with rounded edges occur in cavities in a sphalerite-pyrite-bearing epithermal quartz vein. Also important at the Hanaoka mine.
Aomori: Interpenetrating cubic and cuboctahedral xls to 2.5cm at the Oppu mine.
Fukui: At the Bandoujima lead-zinc mine, cuboctahedral crystals to several cm on edge, often etched or corroded, sometimes with a molten appearance, associated with pyrite and sphalerite in cavities in epithermal quartz veins. At Wasamori, aggregates of cuboctahedral crystals, with faces sometimes corroded. ((same place??)) At the Omodani mine, aggregates of cubic xls with skeletal forms, tarnished bluish, and sometimes covered by blue linarite crusts, in an epithermal chalcopyrite-sphalerite-bearing quartz vein. Argentiferous galena is a major ore mineral in clinopyroxene-bustamite-garnet skarns of the Nakayama orebody at the Nakatatsu mine.
Fukushima: Cubic xls to 15mm, sometimes skeletal, are associated with chalcopyrite in epithermal quartz veins at the Oukubo mine.
Gifu: At the Kamioka Zn-Pb-Ag mine, simple cubic crystals reach 5cm, sometimes modified by octahedral faces, sometimes skeletal figures and molten-appearing edges, associated with sphalerite and overgrown by quartz and calcite, in cavities in contact metasomatosed Shiroji-type lead-zinc ore. The Mozumi orebody at this mine had cubic xls with skeletal modifications, associated with black sphalerite. Although galena is a major ore mineral at this mine, well-developed crystals are scarce. Superb cubic crystals to over 3cm, with somewhat skeletal or hopper-faced individuals in parallel growth, at the Fukuoka mine.
Hokkaido: A minor accessory ore mineral in rhodochrosite veins traversing Tertiary volcanosedimentary rock at several manganese-silver mines, including the Inakuraishi mine, and the Imai-Ishizaki mine. Similarly at the Yakumo mine, where it occurs in beautiful banded structures with pink rhodochrosite, pyrite and sphalerite. A major ore mineral in Ponshikaribetsu, but no good crystals.
Ishikawa: Octahedral xls to 2.5cm, modified by small cube faces, in druses in epithermal chalcopyrite-pyrite-bearing quartz vein at the Kuradani mine. Faces often etched and sometimes with a melted appearance.
Miyagi: A major ore mineral at the Hosokura Pb-Zn-Ag mine, but does not form good crystals. Poorly developed faces are sometimes present on thin, highly corroded crystals. Associated with sphalerite, fluorite.
Nagano: In rhodochrosite ore at the Ryujima manganese mine.
Niigata: Galena cubes associated with sphalerite and chalcopyrite occur in cavities in epithermal quartz veins at the Shiraita mine.
Okinawa: Presently being deposited in chimney-like mixed sulfide bodies over vents in the Jade offshore hydrothermal field.
Ouita: Fairly compact aggregates of cuboctahedral galena crystals, with only the crystal edges visible, are associated with pyrite cubes at Uchinokuchi.
Saitama: Lustrous xls to 5cm in vugs at the Chichibu mine. In the Daikoku orebody here sometimes complex compound tabular pseudohexagonal due to twinning on (111), and as granular xl aggregates sometimes also containing semseyite. Associated minerals include pyrite, arsenopyrite, sphalerite, chalcopyrite, ankerite and other carbonates, magnetite, garnet, diopside, epidote, vesuvianite and ilvaite, in skarn at the contact between Permian limestone and a Tertiary quartz-diorite intrusion with superimposed hydrothermal replacement bodies.
Tochigi: Bismuth-rich and antimony-rich galena forms crystalline masses with a peculiar latticework structure at Nishizawa.
Wakayama: In Kushimoto-cho, galena, sphalerite and chalcopyrite replace 3.5cm Yoldia shell fossils in concretions.
GARRONITE (garon-fusseki)
Kanagawa: (where???)
Shimane: Kuniga, Oki islands.
GASPEITE (ryoh-nikkeru-koh)
Aichi: Pinkish (because of a small amount of Co replacing Ni) gaspeite is found at the Nakauri mine.
GEIGERITE (gaigah-seki)
Fukushima: Red-brown crystals as an alteration of colorless villyaellenite in metamorphosed bedded ore at the Gozaisho manganese mine.
GERMANITE (geruman-koh)
Akita: A minor occurrence of germanite, with typical purple color, was found at the Shakanai mine, in barite-rich stratiform kuroko-type "black ore" derived from seafloor hydrothermal vents, associated with Miocene anhydrite and gypsum, and Miocene dacite-basalt volcanoclastics and dykes. Visible only in polished section under an ore microscope, with arsenian renierite (qv).
Gifu: Kamioka mine.
Shizuoka: A questionable occurrence of germanite is reported from the Kawazu mine.
GIESSENITE (giisen-koh)
Yamanashi: Loose micro-acicular aggregates at the Otome mine, with cosalite in a pneumatolytic quartz vein. Cannot be visually distinguished from the izoklakeite and kobelite here, and in fact much (all???) of the "giessenite" here is really Bi-rich izoklakeite.
GLAUCODOT (gurohkodohto-koh)
Nara: Dohgatani mine.
Wakayama: Reported from the Sanyou mine as white metallic veinlets to 1cm thick, with cobaltite in quartz veins in Mesozoic shale and sandstone. But one such specimen turns out to be alloclasite, and it is not known whether others are too. Also from the Ogake mine.
GLAUCOPHANE (ran-senseki)
Hokkaido: In Mitsuishi and elsewhere in the regionally metamorphosed rocks of the Kamuikotan belt. Glaucophane, riebeckite and chlorite marginally replace hornblende. In albite-glaucophane-quartz schist on Horokanai-tohge, empirically (Na 1.64, Ca 0.18, K 0.10) (Mg 1.93, Fe'' 0.93, Mn'' 0.01) (Al 1.41, Fe''' 0.54, Ti 0.03) Si 8.21 O 22 (OH) 1.31 (Suzuki, J. & Suzuki, Y. (1959) Journ. Fac. Sci. Hokkaido Univ., ser. 4, 10, 349). With aegirine-augite in riebeckite-quartz schist elsewhere in Horokanai-cho. The "crossite" in this area is sometimes glaucophane, sometimes riebeckite.
Niigata: Ohmi district glaucophane schists are limited to the chlorite metamorphic facies, and the dominant amphibole here is intermediate glaucophane-magnesioriebeckite.
Saitama: Glaucophanites in the Kanto mts (& neighboring prefectures' Kanto Mts.?), associated with lawsonite, generally represent a relatively lower grade of regional metamorphism than the area's magnesioriebeckite-bearing schists. Glaucophane in a regional metamorphic chlorite-epidote-albite schist at Akuwara-mura (Saitama???) in the Kanto Mts. is empirically (Na 1.83, Ca 0.38) (Mg 2.16, Fe'' 0.95, Mn'' 0.22) (Al 1.62, Fe''' 0.61, Ti 0.03) (Si 7.69, Al 0.31) O 22 (OH) 2.02 (Seki, Y. (1958) Jap. Journ. Geol. Geogr. 29: 233). With epidote, stilpnomelane, pumpellyite and piemontite in schistose pyroclastics and greenstones in Umezono.
Tokushima: Black needles in glaucophane schist around Mt. Kohtsu-san in Yamakawa-cho. Two analyses give the empirical formulae (Na 1.54, Ca 0.30, K 0.02) (Mg 1.62, Fe'' 1.42, Mn'' 0.02) (Al 1.39, Fe''' 0.46, Ti 0.09) (Si 7.75, Al 0.25) O 22 (OH) 2.09; and a "crossite" (Na 1.84, Ca 0.12, K 0.03) (Mg 1.84, Fe'' 1.22, Mn'' 0.02) (Al 1.11, Fe''' 0.85, Ti 0.03) (Si 7.72, Al 0.28) O 22 (OH) 2.06 (Banno, S. (1959) Journ. Geol. Soc. Japan, 65, 658). Also on Ohtaki-yama (=Mt. Ohtaki-san on the Kagawa border in Waki-cho???).
GMELINITE-Na (sohda-gumerin-fusseki)
Saga: In basalt at Hayata, gmelinite covers the "phacolitic" variety of chabazite, to 2mm, associated with rhombohedral chabazite and calcite. Analysis gave Na 6.84, Ca 0.62, K 0.08 apfu (AM 74, 1337-1342, Nov. 1989).
(prefecture???): Colorless crystals to 6mm in andesite at Mitaki (British Museum specimen).
GOETHITE (shin-tekkoh; "limonite" = bu-seki; kattekkoh)
Aichi: In Takashigahara, goethite occurs as smooth stalactite-like or knobbly plant root-shaped structures. (See origin explained for similar occurrence in Mie-ken.)
Akita: Goethite occurs as "limonite" pseudomorphs after chalcopyrite xls in an oxidized chalcopyrite-quartz vein at the Arakawa mine. A sedimentary bed of "bog iron ore" near Kisakata contains impressions of leaves and branches of dicotyledon plants.
Gunma: Peculiar brickwork-like aggregates composed of obloid blocks of goethite to 6cm, with rounded corners, cemented with lighter-colored vesicular material, at the Gumma iron mine.
Mie: In Ago-cho, light yellowish brown, compact earthy "limonite" forms twisted, sometimes branching, root-like structures to 9mm thick, generally broken into lengths of about 5cm. Because of their occasional humanoid shape, these are known as "takashi-kozou" (novice monks). These formed by oxidation of ferrous iron around plant roots in a marsh, and root remains are sometimes still present in a central tube running through the limonite.
Nagano: Deep brown to brownish black "limonite" pseudomorphs after cubic or pyritohedral pyrite xls to 1.5cm are found in altered andesite tuff at Takeshi and at Shimotakeshi. Pyrite cores are still present in some of them.
Niigata: At the Akadani iron mine, "limonite" stalactites to 16cm long allegedly formed by hydration of the specular hematite ore.
Okayama: Mammillary and stalactitic masses form by oxidation of pyrite at the Yanahara mine.
Okinawa: As sharp, light to dark brown, loose pseudomorphs after striated cubes of pyrite at Uebara, abundantly in stream sand; often mixed with maghemite. On Iriomote island, in recent arenaceous sediments as compact 3 to 5mm thick shells of hollow concretions to 5cm across. These concretions were originally filled with a smectite clay, which shrinks on dehydration, often to hard loose fragments that give the stone its japanese name "naruishi" (rattle stone).
Ouita: Pseudomorphs after pyrite crystals, 3 to 10mm size, with dull luster, at the Kiura mine.
Shiga: Brown to dark brown, elliptical to subangular goethite concretions to 10cm, sometimes multiple concretions stuck together in groups to 17cm, are found at Kita-Ogoto in poorly consolidated sand of an old terrace of Lake Biwa. Externally composed of goethite-cemented sand, internally of a smectite clay which lends these specimens their local name "naruishi" (as described above for the Okinawa locality).
Tottori: As slaggy-looking brown to reddish-brown secondary "limonite" at the Iwami mine, in weathered copper ore.
Yamaguchi: Dark brown metallic pseudomorphs after pyrite, in combinations of cubes and pyritohedra, 2 to 7mm size, from Tabe.
GOLDFIELDITE (gohrudofiirudo-koh)
Aomori: In epithermal gold-silver-bearing veins at the Mutsu mine.
Hokkaido: Teine mine.
Kagoshima: Antimonian goldfieldite (coupled substitution in goldfieldite-tetrahedrite series) at the Iriki mine, associated with hemusite as dark wavy ginguro-type bands in white quartz. It has been suggested that the famously rich "vulcanite" specimen from here, since disappeared, was actually goldfieldite.
Shizuoka: Antimonian goldfieldite can be found at the Kawazu mine, especially the Saraku vein, with argentite as lead-grey granular masses, stringers and veinlets of "ginguro" ore in white quartz-chalcedony veins.
GOLDMANITE (kai-banajin-zakuro-ishi)
Ehime: Green anhedral grains of massive manganoan goldmanite to 3mm occur in massive pink rhodonite at the Kurase mine.
Kagoshima: Dull dark green to reddish manganoan goldmanite from the Yamato mine, was described as the Mn-V-garnet species "YAMATOITE" in 1964. The name was rejected by the IMA because type-locality "yamatoite" contains only about 40% of the yamatoite molecule, but "yamatoite" is still used for the hypothetical Mn-V-garnet molecule. Present in quantity as 0.3mm subhedral to anhedral grains and thin bands in Paleozoic or Cretaceous metasedimentary rhodonite ore from the hanging wall side of the orebody, with rhodochrosite, braunite, etc. Also occurs as euhedral crystals with (110) faces, with very rare green haradaite, brownish green roscoelite, and quartz (and ardennite?) in veinlets in very low-grade ore and the banded chert country rock. Also as larger grains to 1mm in serpentine derived from basic pyroclastic rocks or diabase. The original analysis gave (as wt% oxides) Si 35.76, Ti 0.11, Al 1.90, V''' 24.90, Fe''' 1.13, Fe'' tr., Mn'' 15.92, Mg 0.08, Ca 19.28, Na 0.25, K 0.04, water (ignition loss) 0.54 (from a sample with less than 1% impurities). (D 3.91; RI 1.855; pale greenish yellow in thin section; unit cell: a 11.94743A)
GONNARDITE (gonarudo-fusseki)
Niigata: In amygdules up to10cm wide in altered mid-Miocene basaltic agglomerate and olivine pillow basalts, associated with natrolite and thomsonite, all of which are often covered with younger analcime and calcite, at Maze. Neighboring vugs can contain a large diversity of other zeolite species. Gonnardite, previously misidentified as "high Na-mesolite", occurs with thomsonite at Waniguchi.
Saga: Gonnardite-Na was described from Hayata and Umezaki under the discredited name "tetranatrolite" (tetora-sohda-fusseki). It forms spherical aggregates to 3mm diameter of white radiating needles covering brown phillipsite-Na crystals in hydrothermal veins in olivine basalt. The gonnardite may be covered by younger thomsonite and chabazite, showing increasing Ca/Na over time.
GRAPHITE (sekiboku)
Ehime: Graphite flakes fill scattered spheroidal vugs from 0.5 to 1mm in tobelite at the Ohgidani pottery clay deposit, derived by hydrothermal alteration of a biotite andesite dyke.
Fukushima: Graphite was involved in the formation of pyrrhotite associated with pyrometasomatic chalcopyrite-rich ore at the Yakuki mine.
Gifu: Thin tabular hexagonal crystals, 1mm across, in white crystalline limestone at Yoshigahara. Graphite crystals are found as inclusions in pink corundum (qv) from mudstone metamorphosed by a diorite intrusion, and as metallic films in the country rock, in Kawai-mura. At Hadedani in Kawai-mura, as lustrous flakes in a graphitic schist. In the same general area here as thin platy crystals and massive foliated aggregates as nests and veins in Jurassic high-temperature gneiss of the Ryoke belt, contaminated by intercalated limestone, at the Amou mine, one of Japan's most productive graphite mines. Impure graphite masses here run 60 to 70% carbon. Also as veins in the limestone. Platy graphite crystals 1mm wide are embedded in coarse-grained calcite and columnar green hedenbergite at the Kamioka mine. Also at the Ashidani and Genda mines.
Hokkaido: At the Oshirabetsu mine, abundant ovoid graphite "beans" to 1.5cm form a very unusual conglomeratic-appearing rock constituting a lenticular deposit over 200m long. The graphite nodules easily drop out of the rock, leaving elliptical cavities. Has been mined for its graphite. Also in the Oshirabetsu gabbroic body (Nakanogawa Formation) as euhedral graphite crystals in carbonaceous sediments entrained by the gabbro intrusion.
Ishikawa: As thin plates from 1 to 4mm across in dolomite marble at Gue. Large quantities in argillaceous veins in liparite in Katadani, with graphite ore here up to 90% carbon, but usually less than 60%, with the remainder mostly potassium-rich clay (3.6% K2O).
Kagoshima: At Kataura, elliptical nodules of graphite formed in the centers of limonite masses, surrounded by a layer of kaolin, in diorite. Produced from organic matter metamorphosed by the diorite intrusion. The graphite is composed of 88 to 89% carbon and 11 or 12% "ash".
Toyama: Pods of high quality graphite occur in gneiss in Takanuma and Shimizu. The Sennotani graphite mine, one of Japan's most productive, worked veins of graphite in limestone intercalated in gneiss. As flakes disseminated in limestone in Ashikuraji.
Yamaguchi: Resulting from metamorphosis of coal in Rhaetic sandstone in Torigoye.
GREENALITE (guriina-seki; tosalite = tosa-ishi)
Kouchi: An Fe-Mn silicate described from the Niro mine was named "TOSALITE" (qv) after the historical Tosa province. Later it was considered to be a species intermediate between bementite and greenalite, with a 1:1 Fe:Mn ratio. Presently considered by Japanese mineralogists to be manganoan greenalite, although the Fe:Mn ratio would seem to be closer to kellyite. Also reported from the Matsumo mine.
GREENOCKITE (ryuu-kadomiumu-koh)
Fukui: Yellow crusts on brown sphalerite at the Sennoh mine, sometimes confused with the yellow scaly wulfenite from this locality. Also in the Nakatatsu mine (same district).
Gifu: In the Kamioka mine, secondary greenockite occurs as bright orange-yellow, powdery incrustations to several cm across, associated with sphalerite, galena, hemimorphite and actinolite in fractures of massive hedenbergite in a contact metasomatosed lead-zinc deposit. (Collectors sometimes mistake thin crusts of yellow clay here for "greenockite".) Also at the Horado mine.
Miyagi: At the Hosokura lead-zinc mine, where there was also some commercial Cd production, probably mostly from Cd-bearing sphalerite.
Okayama: With bornite, chalcopyrite and hessite in a white skarn body at the Mihara mine. Also at the Dohchin mine.
Toyama: Kamegai mine.
GREIGITE (gurigu-koh)
Akita: At the Hanaoka mine in Kuroko-type quartz-pyrite massive sulfide ores.
Iwate: Akagane mine.
Niigata: About half of the framboidal pyrites from a drill core in Holocene sedimentary rock at Shirone are weakly magnetic due to ferromagnetic greigite microcrystals in the cores of the pyrite microcrystals forming the framboids.
GROSSULAR (kaiban-zakuro-ishi; hydrous: hipushyuu-zakuro-ishi; hibushu-seki; kasui-kaiban-zakuro-ishi)
(Including the hydroxyl-bearing varieties previously known as "hydrogrossular", "hibschite", and "plazolite" which, rather illogically, are sometimes classified as separate species.)
Chiba: Mineokayama (the hydrous variety "plazolite").
Fukuoka: Granular grossular associated with interstitial bismuthinite, calcite and scheelite in the contact metasomatosed Yokozuru deposit, Sannotake.
Fukushima: Dark brownish dodecahedra about 1cm diameter, composed of (110) and (211) faces, occur in contact metasomatosed limestone at Minamizawa. Brown to reddish brown or brownish yellow dodecahedra with (110) faces, reaching 2cm, composition 83% grossular molecule, are associated with wollastonite and brown prismatic clinozoisite in a limestone-granite contact zone at Tokura-yama (NB: Andradite is also reported from here; more analyses needed). Also with clinozoisite at Fujikaramari. Also at the Nagai mine, and at Sekihata. Some of the skarn xenoliths in the andesite quarry at Tadano are composed of a wollastonite-grossular-diopside assemblage, a hydrothermal alteration of original high-temperature spurrite-gehlenite skarn (qv wadalite). Also as "hydrogrossular" associated with wadalite (qv) in one skarn xenolith enclosed in andesite here. Formed by retrogressive hydrothermal alteration of primary gehlenite. (Is all Tadano garnet hydrogrossular???)
Gifu: Green to lustrous brown, coarse granular or as sharp simple crystals, in white calcite with hedenbergite and ferrobustamite at the Horado mine. Brown grossular occurs with green diopside at the Kasuga mine.
Hiroshima: A magnesian variety of "hibschite", with 3.86 wt% MgO, occurs in skarn at Kushiro.
Hokkaido: White "hydrogrossular" is associated with purple "kaemmererite" and white pectolite as hydrothermal alteration veinlets crossing a chromite orebody in clinopyroxenite at the Tomiuchi mine.
Iwate: Kamaishi mine (qv Andradite). The "hydrogrossular" variety at the Akagane mine and the Matsumori mine.
Kanagawa: Manganoan grossular is associated with piemontite at the Dainichi mine.
Kouchi: "Hibschite" with slawsonite and stronalsite in veinlets crossing rodingite in a serpentinite quarry at Rendai.
Kyoto: "GRA-AL-SP" garnet (grandite-alspite?) with wolframite and quartz at the Kaneuchi mine.
Mie: In pectolite (qv) veins cutting peridotite and serpentinite at Shiraki. The "plazolite" variety at Sugashima.
Nagano: Aggregates of light green to light brownish green translucent 1 to 10 mm crystals at Ikura.
Okayama: Gooseberry-green crystals to 1.5cm at Komoto dam site. As alteration of gehlenite along the borders of clinotobermorite veinlets at Fuka. "Hydrogrossular" in mixtures with bicchulite and other minerals at Fuka, as pseudomorphs after gehlenite. The variety "plazolite" at the Mihara mine.
Osaka: Brown 1cm crystals formed wide crusts associated with epidote in Kashiwara city, along a now inaccessible roadcut.
Ouita: Brown dodecahedral crystals (grossular or andradite?) to 0.5mm sometimes occur as inclusions in transparent danburite crystals from the Obira mine.
Saga: Kyuragi (Kyuragi mine or country rock in Kyuragi city? skarn?).
Saitama: Pale yellowish brown, granular dodecahedral xls form massive aggregates in a contact metasomatosed zone at the Chichibu mine. Vuggy grossular skarn occurs at Hashikakezawa here, containing also ferroaxinite, chabazite-Ca and heulandite-Ca. (Andradite is also found at the Chichibu mine.)
Shimane: Green grossular-rich "grandite" garnet forms skarn with clinopyroxene and various complex Sn-bearing sulfides in the Maruyama orebody of the Tsumo mine.
Toyama: At Kurodake, crusts and crystalline aggregates of sharp, lustrous dark brown to brown, yellowish brown and greenish brown dodecahedral xls to 1cm, associated with slender prismatic quartz xls to 3cm, are found in metasomatosed limestone near contact with a granitic intrusive. This is a manganese-bearing grossular, with 75% grossular molecule and 8.71wt% MnO. Also small yellowish green crystals associated with a fibrous pyroxene. Elsewhere in the lake Arimine area, as brown crystalline aggregates with magnetite and quartz in contact metamorphic rocks. Greenish crystals up to 1.8cm in contact zone between limestone and gneissic granite at Kanetsuriyama (Wada 1904 - old locality, no analysis; grossular or andradite?).
Yamaguchi: Mn-bearing grossular-andradite series garnets are abundant in skarn at the Kiwada scheelite mine, as red-brown xls to 1.5cm and druses, with Mn-bearing hedenbergite, etc. Also in scheelite-bearing skarn at the Kagata mine (error for Ibaragi-ken Kagata mine???).
GRUNERITE (guryuneru-senseki)
Fukushima: With manganoan fayalite and protomangano-ferro-anthophyllite at Suishohyama.
Ouita: In skarn at the Obira mine, grunerite forms light brown to brownish white fine-grained masses known as "yama-no-koruku" (mountain cork), associated with stilpnomelane.
GUSTAVITE (gusutafu-koh)
Hokkaido: With other Ag and Bi sulfosalts in the Sorachi vein of the Toyoha mine. A "gustavite-lillianite series" phase was found in the Ohkubo vein in the Suttsu mine.
Tochigi: An unknown Ag-Pb-Bi-sulfosalt in mesothermal Cu-Zn-Pb-Bi-Mo-W veins at the Oizawa mine, ~Ag 0.67 Pb 1.67 Bi 2.67 S 6, may be gustavite or lillianite.
GYPSUM (sekkoh)
Akita: At the Hanaoka mine, colorless transparent to whitish, slender prismatic tabular gypsum crystals to 30cm occur in cavities in a Kuroko-type massive sulfide deposit composed mainly of pyrite, with some quartz, in a green tuff formation. Colorless to white, transparent to translucent, parallel fibrous aggregates, no crystals, in sulphide ore at the Kosaka copper mine. Also at the Nagaki mine and the Osarizawa mine.
Gumma: Platy prismatic xls to 1cm in clay beds at Akaginemura. Rough swallowtail twins, 4 to 5cm long, in fissures in shale at Gouhara. Single crystals embedded in soft sediment at Satobara ((same places???)).
Hyougo: Short prismatic xls averaging 3cm, showing (111), (110) and (010) faces, were found as a secondary mineral in fractures, associated with minor stannoidite, in a chalcopyrite-bearing quartz vein at the Kanagase orebody of the Ikuno mine.
Ibaragi: Elongated colorless crystals laying flat in thin fissures in bedded cupriferous massive pyrite ore at the Akazawa mine.
Ishikawa: Transparent prismatic xls to 10cm, with (110), (010) and (111) faces, in clay strata in a Kuroko-type deposit at the Noto mine. Gypsum is also associated here with pale pink anhydrite. Also at the Wakayama mine.
Kanagawa: At Ouwakudani, solfataras in an active Hakone volcano crater produce colorless transparent, thin tabular xls showing (110), (010) and (111) faces, sometimes as radial aggregates.
Miyagi: Aggregates of transparent prismatic xls showing (110), (010) and (111) faces, occur interstratified with tuff at the Miyazaki mine, which also has gypsum as the compact white fibrous "alabaster" variety with silky luster, and as transparent anhedral plates. Alabaster also at Narigo.
Nagano: White translucent, rough-surfaced single crystals, with abundant swallowtail twins, embedded in soft sediments at Sanoyama.
Rikuchuu: (which prefecture???) A gypsum stratum, 6cm thick, upper part fibrous, lower transparent, in Tertiary tuff at Katchi (near Yuta).
Shimane: At the Udo mine, slender transparent xls to 10cm, showing (110), (010) and (111) faces, and sometimes even fibrous, comprise massive gypsum ore in a Kuroko-type deposit. Sometimes associated with pale blue, fibrous celestite. Columnar crystals to 73cm long are found in a montmorillonite zone in the surrounding Miocene altered rhyolitic tuff. Also at the Iwami mine, the Ohta mine and the Wanibuchi mine.
Tokyo: Sharp transparent swallowtail twins on Ogasawara-jima. Sharp, colorless transparent crystals to 3.5cm in crevices of rock ejected during the 1901 explosion of Torishima.
Yamanashi: Transparent sharp prismatic xls to 2cm, often as swallowtail twins, as loose floaters in clay at Yagosawa. A 3m-thick bed of gypsum, with a finely granular white layer in the middle, in Misaka Series tuff at Mogura.
GYROLITE (gairoru-seki)
Yamagata: Aesthetic specimens come from vugs in olivine dolerite at Irakawa, together with natrolite, thomsonite, analcime and opal. Tiny acicular crystals form foliated aggregates to 1cm long.
Yamanashi: Creamy white, radiating crystals form rosettes to 2cm across on rhyolite at Shimohatsukari (Hatsukari).
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