Encyclopedia of Japanese Minerals (Go to Intro Page)
by Alfredo Petrov
Minerals Starting with "N"
"NAEGITE" = U-Th-bearing ZIRCON (qv)
NAGASHIMALITE (nagashima-ishi; nagashima-seki)
Gumma: The type locality for this rare Ba-V borosilicate is the Mogurazawa manganese mine, where it forms vitreous to submetallic-adamantine greenish black elongated tabular-acicular blades to 5mm, with no cleavage, and sub-parallel aggregates, embedded in massive pink rhodonite in cobbles in the creekbed below the mine, apparently eroded from the country rock and not from the mine ore itself. Associated with tiny quartz veinlets, rhodochrosite, barite, barian roscoelite, suzukiite and alabandite, sometimes with minor copper- and zinc- sulfides. Unfortunately many so-called "nagashimalites" in collections are misidentified, in reality being tiny rhodonite or rhodochrosite grains with a green-tarnished black oxide coating, or dark sulfide grains with a shiny greenish tarnish. Among Japanese systematic species collectors, this is one of the most commonly overoptimistically identified minerals; Caveat emptor!
"NAGATELITE" (= phosphate-rich ALLANITE (qv) from Ishikawa-ken.)
NAGYAGITE (najiagu-koh)
Hokkaido: Obetsuzawa mine.
Shizuoka: Bismuthian nagyagite was found at the Rendaiji (Kawazu) mine with stringers of tetradymite and tellurium in an epithermal chalcedonic quartz vein.
NAKASEITE (nakase-koh)
Hyougo: The type locality for this lead-grey sulfosalt - Pb4Ag3CuSb12S24 - is the Nakase mine, where light grey, striated thick tabular crystals up to 3mm are embedded with sphalerite in freibergite or argentian tetrahedrite and quartz in a hydrothermal gold-bearing quartz-stibnite vein crossing Paleozoic sediments. Nakaseite is sometimes considered in North America to be merely a variety of andorite ("Cu-rich andorite XXIV"), but it has a different symmetry and different cell size, so Japanese mineralogists generally consider it to be a separate species, with essential copper. (Monoclinic, with very complicated twinned lattice, space group Plla, P1/a; unit cell: a 13.02A, b 19.18A, c 102.24A (24x4.26), beta 90 degrees, Z 24; light to dark grey in polished section; D 5.37 (calc.), 5.30 (meas.); tarnished by 1:1 HNO3, stained brownish by 40% KOH, effloresces instantly in aqua regia and turns black.)
NAKAURIITE (nakauri-seki)
Aichi: The type locality for this very hydrous copper sulfate-carbonate is the Nakauri nickel-copper mine, where it forms abundant light blue films or aggregates of sky blue or bluish white, fibrous to minute acicular crystals individually up to 0.2mm long and 0.006mm wide, sometimes as radial sprays, in narrow fractures in serpentinite formed by alteration of gabbro; associated with chrysotile, artinite, pyroaurite, brochantite and malachite. The serpentinite host rock contains djurleite and native copper. The tunnels of this mine, closed over 60 years ago, are still accessible but extremely dangerous; cave-ins have occured after minor earthquake tremors of as little as magnitude 2!
Saitama: At Ninomiya (of different color shade than at the type locality).
NAMANSILITE (namanshiru-kiseki)
Iwate: Some of the "Mn-alkali pyroxene" with kozulite at the Tanohata mine might be namansilite?
Ouita: Forms very thin, dark red-brown veinlets, to 1mm wide and several cm long, at the Shimoharai mine, traversing light brownish pink meta-chert in very low-grade Mn ore. Alters to earthy ochre-brown material within 1cm of the surface of chert boulders.
NAMBULITE (nanbu-ishi; nanbu-seki)
Fukushima: Nambulite occurs as large, bright reddish- or brownish-orange to orange-yellow coarse granular masses and veinlets to 2cm in a braunite-rich black ore band at the Gozaisho mine, a stratiform manganese deposit in metamorphic chert. Usually seen only as cleavages; complete crystals are short prismatic but very rare. Associated species include greyish green tephroite, pink rhodonite and black hausmannite.
Iwate: The type locality for this Li-Mn pyroxenoid is the Funakozawa mine, where it forms orange-brown or reddish orange-brown, coarse prismatic crystals up to 8mm long, with vitreous luster and three cleavage directions, aggregated into veins up to 5cm thick cutting massive braunite-rhodonite ore. Associated species are albite, rhodochrosite and neotocite. Nambulite forms an isomorphous series with natronambulite, and some specimens from here are at the midpoint in the series.
NATROALUNITE (sohda-myohban-seki)
Gumma: In concentric growth with huangite and minamiite (qv) in minute zoned "minamiite" crystals in hydrothermally altered two-pyroxene andesite around hot springs at Okumanza.
Shizuoka: Thin hexagonal tabular or lamellar crystals, sometimes in rosette-like aggregates, white with a yellowish tint, line drusy vugs at Ugusu hot springs, in hydrothermally altered rhyolite. (Mined with alunite for alum and fertilizer at the Ugusu alunite mine.) At Hetamura as veins composed of rosettes of transparent white, thin hexagonal lamellae to 1cm across, associated with sulfur in andesite. Also at Shirakawa.
NATROAPOPHYLLITE (sohda-gyogan-seki)
Okayama: The type locality for this sodium-dominant member of the apophyllite group is the Sanpoh quarry, where it occurs in white skarn as colorless, brownish yellow to yellowish brown or white, vitreous to pearly, simple prisms terminated by dipyramids - (100) and (111) faces - with perfect basal cleavage, formed by fluorine-rich fluids injected into primary andradite-xonotlite-wollastonite-diopside-quartz skarn. Crystals are alternately zoned with fluorapophyllite, and an intermediate apophyllite member (K:Na = 1:1) also exists here. Other associated species are zeophyllite, cuspidine, calcite, and minor magnetite and native bismuth.
NATROJAROSITE (sohda-tetsu-myohban-seki)
Kyoto: Multi-cm fine-grained orange crusts coating fissures on grey rock in Sakyo-ku (Saikyo-ku sic??) in Kyoto city.
NATROLITE (sohda-fusseki)
Chiba: Sharp gemmy square-prismatic xls to 5mm long as lawn-like aggregates at Futomi. Natrolite from Kainagisa (= Futomi???) exhibits {110} and {111} faces and is reportedly slightly monoclinic (X^b=0.5 degrees) (Akizuki, M. and Harada, K. (1988) Am. Min. 73, 613-618). In Paleocene andesite lava at Nagasakibana. Also at Isomura (overlap locality???).
Ehime: Radiating spheres to 2.5cm across, with calcite xls and apophyllite on datolite in cavities in lower zone of biotite andesite at the Makinogawa quarry and elsewhere in Kuma-machi.
Nagasaki: Fibrous natrolite occurs in amygdules of altered basalt conglomerate exposed on the seashore at Chojabaru. Easily confused with the more abundant associated thomsonite of similar habit. Also with stilbite.
Niigata: At Maze, fibrous or acicular terminated natrolite crystals up to 2.5cm, averaging 1cm, form radial spherules and sprays to 3cm in cavities in a Miocene basaltic agglomerate. Varies from colorless transparent to white translucent. Commonly covering older thomsonite-gonnardite aggregates, and itself covered by younger transparent analcime and minor calcite, sometimes with small calcite rhombs impaled on the natrolite. Also with pale blue apophyllite.
Saga: At Hayata, as white spherules to 8mm in vugs to over 8cm with calcite and chabazite.
Yamagata: Well-known classic aesthetic specimens, globular sprays up to 4cm, associated with thomsonite, gyrolite, opal and analcime in vugs in olivine dolerite at Irakawa. Thomsonite balls often form the center of the natrolite sprays. Also at Onisaka pass.
NATRONAMBULIT (sohda-nanbu-seki)
Iwate: The type locality for this pinkish orange to orange-yellow Na-Mn pyroxenoid is the dumps of the Matsumaezawa orebody of the Tanohata mine, where it is found in low-grade, thermally metamorphosed Mn ore as coarse-grained (up to 7mm grains) aggregates to 3cm, associated with Mn-rich aegirine, Mn-rich arfvedsonite, quartz, rhodonite, albite and serandite near, but not in contact with, a braunite band. Natronambulite also occurs here in a pegmatitic vein with albite, microcline, quartz and serandite. Natronambulite has a vitreous luster, two perfect cleavages, a density of 3.51 and hardness 5.5 to 6. Alleged by at least one seller to be highly fluorescent red under SW UV, but many specimens sold as "natronambulite" do not fluoresce, and it is otherwise visually indistinguishable from nambulite. Some "nambulite" specimens from the Funakozawa mine are actually at the midpoint in the nambulite-natronambulite series.
NAUMANNITE (nauman-koh)
Hokkaido: Reported at the Sanru mine.
Kagoshima: Microscopic grains with polybasite, pyrargyrite, stephanite and argentite in ginguro-type banded silver ore in the Arakawa tunnel at the Kushikino mine. And presently being mined in young (1 million year old) epithermal adularia-quartz veins at SumitomoÕs Hishikari mine, where it is associated with electrum, pyrargyrite and aguilarite in black "ginguro" bands.
NEOTOCITE (neotosu-seki)
(often labelled "penwithite" in old japanese collections)
(Widely distributed in japanese metamorphosed manganese ores, often in late-stage veinlets with carbonate and occasional barite. Consistently yellowish brown in transmitted light, which is remarkable considering its wide range in density (2.7 - 2.9) and RI (1.48 - 1.59).)
Aichi: As fractured, decimeter-size masses of "penwithite", submetallic black on the surface, resinous brownish black inside, with rhodonite and pyroxmangite at the Taguchi mine.
Gifu: Chocolate-brown resinous, compact masses to several cm, with chert at the Ushimaki (Tsurumaki?) mine in Minokamo city. Neotocite-barite veinlets cut fine-grained metasedimentary Mn ore composed mainly of hausmannite and carbonate, at the Nagashima mine. Also as "penwithite" from the Ittanda (Itsutanda?) mine.
Hiroshima: An amorphous Mn silicate from the Takayama mine (a branch of the Bunkoh mine), described in 1927 as the new species "BUNKOLITE" (named after the larger mine), might be a variety of neotocite, although it has a considerably higher density (3.354) than other japanese neotocites. Black to dark brown, translucent, with resinous to vitreous luster. Associated with rhodochrosite and "Mn dioxide" as a primary mineral in Paleozoic sedimentary manganese ore. Analysis (as wt% oxides) Mn'' 46.56, Mn''' 18.89, Si 20.61, Al 2.09, Fe''' 1.65, Mg 1.63, Ca 1.07, Cu 0.14, water- 4.00, water+ 5.89, Total 102.53. (Streak dark brown; fracture conchoidal, brittle; H 3.5.)
Iwate: Associated with nambulite in braunite-rhodonite ore at the Funakozawa mine. A common ore mineral in folded metasedimentary Mn deposits at the Noda-Tamagawa mine, with hausmannite and tephroite; as late-stage carbonate-neotocite-bementite veinlets cutting rhodonite; and as brownish black to almost colorless amorphous material (neotocite-allophane series?) Forming massive ore and as cement between grains of rhodonite, quartz, albite and a chlorite-like mineral. Also as "penwithite" from Hinosawa.
Shiga: An accessory constituent of complex Mn-silicate-carbonate-oxide ore at the Ioi mine. Also as younger barite-neotocite veinlets, lined with bementite along their edges, cutting across alleghanyite-galaxite-hausmannite ore.
Shizuoka: Neotocite forms reddish black or deep brown to pale brown, glassy-resinous, friable masses with conchoidal fracture as a late-stage hydrothermal mineral in an epithermal gold-silver-quartz vein at the Rendaiji (Kawazu) mine.
Yamaguchi: At the Renge mine, in pyroxmangite-garnet-carbonate metasedimentary Mn ore; and in late-stage carbonate-bementite veinlets traversing quartz-carbonate-pyroxmangite ore.
NEPHELINE (kasumi-ishi)
Hiroshima: Kushiro.
Okayama: At Fuka. Also in Pliocene alkali basalts (basanite) on Kajikoyama and Sukumoyama, with Na 15.6, K 3.44, Ca 1.42 and 15.9, 3.96, 1.06 respectively (as oxide wt.%).
Shimane: In zeolite-bearing grey fine-grained nephelinite in Hamada city, the first japanese locality for nepheline. And in Pliocene alkali basalt (basanite) on Noyamadake, with an analysis equivalent to Na 0.88, K 0.09, Ca 0.03 apfu. Also at Nagahama (=Hamada?).
NEPOUITE (nupoa-seki)
(Includes much of the material previously reported as "garnierite", which needs to be reanalyzed. Might include some nimite or pecoraite - although these species have not yet been reported from Japan - or other Ni-bearing phyllosilicates.)
Fukushima: Confirmed nepouite at Atagoyama ("Atabuyama"?).
Hokkaido: "Garnierite" at the Kamikawa mine.
Mie: Confirmed nepouite at Sugashima.
Nagano: "Garnierite" at the Miyagawa mine and the nearby Shizuke mine, where they occur in lateritic deposits concentrated by the weathering of weakly Ni-bearing serpentine.
Ouita: "Garnierite" at the Wakayama mine.
NICKELBISCHOFITE (nikkeru-bishyofu-seki)
Gumma: "Nickelbischofite" was deposited as a green, deliquescent, minor constituent of powdery alunogen and other sulfate sublimates in a fumarole on Shirane-san volcano, which was the first (1957) world locality for this rare, hydrous nickel chloride. However, it was not named or adequately characterized at that time, and was later badly named (because it is not structurally related to bischofite) when finally described in 1979 on Texan (synthetic?) material! Obviously needs further study, redescription and renaming.
NICKELINE (koh-hi-nikkeru-koh)
Hyougo: Nodular masses to 40cm diameter of concentrically banded pink nickeline and light grey gersdorffite, with inclusions of minute pyrrhotite xls, along with microscopic pentlandite and breithauptite, at the Natsume mine, in shear zone fractures of serpentinite in the Yakuno ultramafic complex. Usually seen in japanese collections cut in half and with interior polished to show the banding.
Saga: Rare accessory mineral in metamorphosed bedded Mn-silicate-carbonate ore at the Kyuragi mine.
NIFONTOVITE (nifontofu-seki)
Okayama: Colorless or greyish, narrow bladed crystals to 3cm, rarely doubly-terminated, in high-temperature, borate-bearing skarn on the 4th Level of the Fuka mine, the second world locality for nifontovite. In a Ca-borate vein averaging 10cm wide (max. 2m), composed of takedaite, nifontovite, olshanskyite, sibirskite, parasibirskite, henmilite and pentahydroborite. Can contain black kusachiite inclusions. Formed by late hydrothermal alteration of sibirskite or parasibirskite.
NIIGATAITE (niigatalite) (niigata-seki) (IMA #2001-055)
Niigata: First found on Miyabana beach and named after the prefecture, this strontium analogue of clinozoisite (or Al-analogue of strontiopiemontite) is found as rare, pale grey with yellowish green tint, or greyish green to yellowish green, anhedral to subhedral crystals to 1mm, intimately associated with darker green chlorite, in a violet rodingite boulder composed mainly of a compact platy aggregate of violet diaspore, and coarse divergent bundles of white prehnite to 3cm, derived from serpentinite melange. Later found in prehnite-chlorite rock without diaspore. Minor associates include zircon, cinnabar, galena and strontian clinozoisite (making quantitative analysis essential for identification). (H 5-5.5, good cleavage on {001}, brittle; transparent to translucent, vitreous luster, RI 1.67 - 1.725; with violet anomalous interference color; nonfluorescent; white streak; calc. D 3.64; ) Analysis showed (as oxide wt%): Mg 0.07, Ca 14.09, Mn'' 0.22, Sr 14.75, Al 24.86, Fe''' 7.08, Si 35.49, Ti 0.75, showing that the only major replacements are Ca for Sr, and Fe''' for Al; there may be a complete series to clinozoisite. Many specimens of "niigataite" circulating on the rare species market may have been broken down from an originally niigataite-bearing boulder, but the fragments on sale do not contain any of that species anymore (Caveat emptor!).
NINGYOITE (ningyoh-seki)
Okayama: The type locality for this hydrous uranium phosphate (with minor Ca and Ce) is the unoxidized portion of the sandy matrix of a Pliocene lacustrine basal conglomerate overlying granitic rocks at the Ningyoh-tohge mine, as impregnations and as thin coatings on pyrite, apatite and gypsum, associated with minor kaolinite, montmorillonite, chlorite, biotite, calcite, hypersthene, coffinite, uraninite, marcasite, sphalerite, and detrital rutile, quartz, feldspar. Ningyoite is transparent pale green, or brownish green to brown in transmitted light, but generally looks a sooty black because of finely divided carbonaceous and pyritic impurities. Forms euhedral columnar crystals from 0.005 to 0.1mm, terminated by right and left disphenoids; also acicular, or as elongated lozenges. Highly radioactive. (Some references have incorrectly described ningyoite as filling cracks and cavities in lemon-yellow oxide-zone uranium ore derived from pegmatite.) This deposit was discovered in 1955 (qv Autunite) and ningyoite became the main ore mineral after 1957 when the unoxidized zone was worked.
Tottori: The Ningyo-Tohge deposit straddles the Okayama-Tottori border, and some specimens are labelled as coming from adits on the Tottori side, such as the Tohgoh mine.
NITRATINE (chiri-shohseki)
Tochigi: At Ohya (probably deposits on the walls of the underground tuff dimention stone mines?).
"NOGIZAWALITE"
(A mixture of the inadequately described "AWAZULITE" (qv) with zircon.)
NORDSTRANDITE (norudosutorando-seki)
Gunma: Creamy white earthy crusts with sponge-like holes, on light grey rock at Tatarazawa, Fujioka city.
Mie: Associated with chromian dawsonite and chromian alumohydrocalcite in the crush zone of "black schist" in the Median Tectonic Line, Sana area.
NSUTITE (yokosuka-seki; ensuuto-koh)
Aichi: In 1937 the new mineral "yokosukaite" (or "yokosukalite") was described from the south side of Ishizuka-tohge in what used to be Yokosuka village (hence the name; now part of Hazu-cho), where a small manganese mine operated just before WWII. Its major powder XRD lines did not match any MnO2 mineral known at that time: 2.4 (10), 4.3 (9), 2.1 (5), 6.5 (3), 2.8 (3), 1.8 (2). In 1961 this pattern was shown to match synthetic gamma-MnO2. (This species was re-named in 1962 when described from Nsuta, Ghana, 25 years after its discovery in Japan, so the name yokosukaite ought to have priority.) Forms black or blackish brown compact masses with light brown to yellowish brown rhodochrosite in the exposed oxide zone of a late Paleozoic or early Mesozoic metasedimentary rhodonite-spessartine deposit (Ryohke metamorphic belt), once a popular garnet-hunting spot for collectors, who paid no attention at all to the ugly Mn oxides. Most of the hillside has since been dug away and a factory constructed on the spot, so no more of this material is available. (H 4)
Iwate: With manjiroite in oxidized rhodonite-tephroite-rhodochrosite ore at the Kohare mine. Also at the Noda-Tamagawa mine, and the Tachikawa mine.
Osaka: (Where???)
NUMANOITE (IMA 2005-050) (numano-seki)
Okayama: Type locality is the copper-bearing calc-borate skarn at Fuka, = the copper analogue of borcarite, with which it forms a partial series. Thin tabular crystals to 2mm, light bluish green, or more commonly as colored zones included in colorless borcarite crystals. (Some so-called "numanoite" on sale in Japan is just plain borcarite; Caveat emptor!) (Perhaps also comprises some of the light blue alteration crusts associated with henmilite??? Some of these give a borcarite XRD pattern, but some give no distinguishable XRD pattern and have been called amorphous "chrysocolla".)
"NUNAKAWAITE" (see STRONTIO-ORTHOJOAQUINITE)
NYBOEITE (nibyoh-senseki)
Niigata: With eckermannite, rengeite, etc, in blue and violet jadeite boulders and pebbles in the Kotaki river and on the Ohmi coast.
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