J. Min. Petr. Econ. Geol. 88, 517-524, 1993

Gaspeite, glaukosphaerite, mcguinessite and jamborite in from Shinshiro City, ,

Satoshi MATSUBARAand Akira KATO Departmentof Geology,National Science Museum Shinjuku,Tokyo 169, Japan

Gaspeite, glaukosphaerite, mcguinessite, and jamborite were found in the old gallery of the

Nakauri mine, Shinshiro City, Aichi Prefecture, central Japan. The last one was also found in

a quarry at Kamewari Pass nearby the mine. Gaspeite is cobaltian with Co/(Ni+Co)=0 .28•`0.31

and greyish pink in colour despite Ni>Co in mole ratio. Glaukosphaerite has Ni/(Ni+Cu)=0 .42 •` 0.49 and CoO up to 5 wt. %. Cobaltian varieties of these species are new to them. Mg/(Mg+

Cu) in mcguinessite ranges 0.61 to 0.65, which is higher than those of the originally described

material. Jamborite from Kamewari Pass has Fe/(Fe+Ni)=0 .29•`0.32, extending the compositional range to Fe-rich side. All of them are thin crustification on walls cutting

genetically responsible for circulating meteoritic water. Metallic elements in these

minerals seem to owe the origin to the underlying -bearing serpentine, heazlewoodite , cobaltpentlandite, and djurleite. The substitution relation of Co2+ for Ni2+ in these carbonates

suggests the similarity of their geochemical behaviours under the condition in old galleries, where

such solid solutions were readily formed.

Keywords: Gaspeit, Glaukosphaerite, Mcguinessite, Jamborite

jamborite from a quarry at Kamewari Pass I. Introduction near the mine. All of them are crustification

The most predominant forms of secondary on fracture walls in serpentinite and probably nickel or cobalt minerals are represented by of the youngest formation among secondary their arsenates, sulphates and carbonates, and minerals thereat. The described minerals owe the first two are more common, reflecting the their origin to the transportation of their essen components of their principal minerals includ tial components, nickel, cobalt, copper and iron. ing sulphur or arsenic as their essential compo nents. Therefore, the appearance of nickel II. Occurrence carbonates requires the prevalence of any spe The ore deposit of the Nakauri mine (N 34•K cial condition as considered here in relation to 51', E 157•K31') is developed in serpentinite the description of gaspeite, glaukosphaerite, involved within Mikabu zone, and located about mcguinessite and jamborite, all of them being 7km SSE of Shinshiro Station, of the first finds in Japan. Japan Railway, Tokai Company Ltd. It was The present description is for their occur worked for iron and copper till 40 years ago. rence, chemistry and X-ray powder study on The principal ore minerals include magnetite, gaspeite, glaukosphaerite and mcguinessite djurleite, and chalcocite. Magnetite is the from the Nakauri mine, Shinshiro City, and on most predominant and occurs as disseminations

(Manuscript received, Juiy 12, 1993; accepted for publication, August 10, 1993) 518 Satoshi MATSUBARA and Akira KATO

Fig. 1. Scanning electron photomicrograph of the Fig. 2. Scanning electron photomicrograph of the aggregate of glaukosphaerite. aggregate of jamborite. Field view 30•~25 ƒÊ m.

in serpentinite as minute to sizable dimensions. allophane have been reported (Suzuki et al.,

Larger ones involve a small amount of djurleite 1976). The materials of the present finds are or digenite. Also, aggregates of heazlewoodite not ordinary secondary ones but thin with cobaltpentlandite are found in association crustifications on fracture walls of serpentinite with magnetite, and considered to be products in the gallery or minute spots on secondary of desulphurization of Co-bearing . serpentine precipitated from circulating Besides them, native copper, chalcopyrite, bor meteoritic water under a superficial condition. nite, digenite, cuprite, tenorite, malachite, azur Gaspeite forms light greyish pink thin ite, and brochantite are found (Kato and Ma crust. Under the electron microscope the crust tsubara, 1971; Matsubara and Kato, 1979). consists of the aggregate of spherulitic bodies

Also, a new mineral nakauriite and Cu-bearing of 5•`10ƒÊm across. The crust occupies an

Table 1. Chemical compositions of gaspeite

1. Gaspeite. Nakauri mine, Aichi Prefecture, Japan. The present study. The lowest CoO analysis. 2. Gaspeite. Ditto. The highest CoO analysis. 3. Gaspeite. Gaspe Peninsula, Quebec, Canada. After Kohls and Rodda (1966). *includes CO2 42.0 and H4Mg3Si2O9 2.1 wt.%. Gaspeite, glaukosphaerite, mcguinessite, and jamborite in serpentinites 519

Table 2. Chemical compositions of glaukosphaerite

1. Glaukosphaerite. Nakauri mine, Aichi Prefecture, Japan. The present study. The lowest CuO, the highest CoO and NiO analysis. 2. Glaukosphaerite. Ditto. The highest CuO analysis. 3. Glaukosphaerite. Kambalda, Australia. After Pryce and Just (1974). *Fe2O3. **includes CO2 21.70, H2O* 9.85, H2O- <0.01 wt.%.

area of a centimeter across in maximum sur spots forming crust on aggregates of chrysotile rounded by glaukosphaerite without exception. that cuts serpentinite. The spots reach 1mm

This forms dull light green thin crust with or in maximum dimension. Under the electron without gaspeite. Under the electron micro microscope, the individual grains have tabular scope, the individual crystals have thin tabular form. The description on jamborite was made form as well as malachite with the same out on the material from a quarry at Kamewari look from the same locality (Fig. 1). Pass located about 1.5km east of the mine (N

Mcguinessite forms light greenish blue minute 34•‹51', E 137•‹33.5'). It forms greenish yellow

Table 3. Chemical compositions of mcguinessite

1. Mcguinessite. Nakauri mine, Aichi Prefecture, Japan. The present study. The lowest MgO analysis. 2. Mcguinessite. Ditto. The present study. The lowest CuO analysis. 3. Mcguinessite. Red Mountain, California. After Erd et al., (1981). 520 Satoshi MATSUBARA and Akira KATO

Table 4. Chemical compositions of jamborite

1. Jamborite. Kamewari Pass, Aichi Prefecture, Japan. The present study. The lowest FeO analysis 2. Jamborite. Ditto. The highest FeO analysis. 3. Jamborite. Northern Apennines, Italy. After Morandi and Dalrio (1973). *includes Coo 2.4 wt. %. The original figures are given by wt.% of metals. They are converted here by the present authors. powdery crust on deep greenish grey ser by spionkopite. In all the grains djurleite has a pentinite, which involves a Ni-bearing serpen concave or linear outline against magnetite. tine as the essential constituent. Under the The grains of heazlewoodite are smaller in electron microscope, tiny hexagonal tablets are quantity and size, 0.0n mm across, and form observed (Fig. 2). The crust is more lustreous aggregates of 0.n mm across with or without than above carbonates due to the higher re djurleite enclosed within magnetite. Bornite fractive indices. The material from the mine occurs as very small drop-like bodies within occurs in association with glaukosphaerite. It magnetite aggregate or minute grains in associ is less yellowish than the material from Kame ation with djurleite. The reconstructed order wari Pass quarry. of formation of opaque minerals is: magnesio- Ore microscopic observation of a piece of chromite-magnetite-heazlewoodite-djurleite- magnetite ore covered by thin film of glaukos spionkopite. phaerite informed that the included opaque All the examined materials were collected minerals are magnetite, magnesiochromite, in the gallery where the described carbonates djurleite, heazlewoodite, bornite and possibly are grown on gallery walls and on fracture spionkopite in the order of decreasing quantity. walls near excavated parts. Thus, it is very Magnesiochromite forms octahedral or dodeca likely that the excavation of gallery provided a hedral idiomorphs of 0.n mm order perfectly favourable site of precipitation of carbonates. hosted by magnetite, which partially veins them. Magnetite is composed of aggregates of III. Chemical Analyses anhedral grains of 0.n to 0.0n mm across. Electron microprobe analyses of gaspeite, Djurleite forms aggregates of a millimeter size glaukosphaerite, mcguinessite, and jamborite within magnetite aggregates and consists of using Link Systems energy dispersive X-ray randomly oriented mosaic crystals. Some spectrometer are given in Table 1, 2, 3, and 4, parts of the aggregates are replaced or veined respectively. The tabulated analyses are Gaspeite, glaukosphaerite, mcguinessite, and jamborite in serpentinites 521

Table 5. X-ray powder patterns of synthetic NiCO3, gaspeite and synthetic CoCO3

1. Synthetic NiCO3 . JCPDS Card No. 12-771. 2. Gaspeite. Nakauri mine, Aichi Prefecture, Japan. Co/Fe rad. Diffractometer method. The present study. 3. Synthetic CoCO3. JCPDS Card No. 11-692.

selected to demonstrate their compositional original analysis, in which S is handled as S and variation ranges. SO3. In the present case, S is regarded as SO3 Gaspeite analyses are characterized by only. The variation ranges of all the detected high and slightly variable CoO contents. and quantitatively measured constituents are Co/(Ni+Co) ranges from 0.28 to 0.31. The rather small. That is, the ratio (Ni+Cu): Fe compositional variation of glaukosphaerite is is close to 7:3, where Cu is very low. The S given as slightly fluctuating figures of all the content using the basis total cations except S= components. CoO ranges 3.00 to 5.34 wt. %. 1 is less than 0.05. Seeing from the crystallo Cobalt is a new subordinate constituent to these graphic data and the most probable expected minerals. Ni2+ and Co2+ have similar behav crystal structure, it is unlikely that the cationic iours under such a superficial condition possibly sites are differentiated. Therefore, the Fe in neutral to weakly alkaline. Mcguinessute is now found to be capable of containing more MgO than the original materials (Erd et al., 1981) beyond Mg:Cu=3:2, and the ratio varies from 1:1. The back scattering electron image indicates that Mg is concentrated in the medial zones in the spots, which are composed of radially aggregated tablets (Fig. 3). The chemical compositions of the present jamborite are different from those of the origi nal material (Morandi and Dalrio, 1973). The former includes very high Fe and low Ni, both Fig. 3. Backscattered electron image of mcguines of which are here given as FeO and NiO, tenta site. Note the dark rings around cores of tively. The S contents are less than 1/3 of the radial aggregates of blades. Bar=10ƒÊm. 522 Satoshi MATSUBARA and Akira KATO

Table 6. X-ray powder patterns of glaukosphaerite and mtguinessite

1. Glaukosphaerite. Nakauri mine, Aichi Prefectur, Japan. Co/Fe rad. Diffractometer method. b=broad. The present study. 2. Glaukosphaerite. Kambalda, Australia. b=broad. After Pryce and Just (1974). 3. Mcguinessite. Nakauri mine, Aichi Prefecture, Japan. Co/Fe rad. Diffractometer method. b=broad. *= intensity could not be measured due to the overlapped diffractions of serpentine mineral. The present study. 4. Mcguinessite. Red Mountain, California. After Erd et al., (1981).

the present jamborite is a vicarious constituent ters is in accordance with those derived from to Ni. the values of synthetic NiCO3 and CoCO3, that is, a=4.609 and c=14.737A for NiCO3 (JCPDS IV. X-Ray powder studies Card No. 12-771), and a=4.659 and c=14.957A Gaspeite, glaukosphaerite and mcguines for CoCO3 (JCPDS Card No, 11-692) (Table 5). site from the Nakauri mine, and jamborite The pattern of glaukosphaerite is not com from Kamewari Pass quarry were subjected to plete but lacks some weaker diffractions and the X-ray powder diffraction study. They are slightly different in minute points as compared given in Tables 5, 6, and 7, respectively. with those of the original description (Pryce The pattern of gaspeite is indexed on a and Just, 1974) and of the material from hexagonal cell with a=4.648 and c=14.897A. Kasompi (Deliens, 1975). The present pattern However, neither axial ratio nor cell parame corresponds rather to that of the latter, which Gaspeite, glaukosphaerite, mcguinessite, and jamborite in serpentinites 523

Table 7. X-ray powder patterns of jamborite and unnamed nickel hydroxide of Jambor and Boyle (1964)

1. Jamborite. Northern Apennines, Italy. After Morandi and Dalrio (1973). 2. Jamborite. Kamewari Pass, Aichi Prefecture, Japan. Co/Fe rad. Diffractometer method. The present study. 3. Unnamed nickel hydroxide. Rock Creek, British Columbia, Canada. After Jambor and Boyle (1964).

is indexed on a triclinic cell after the reference [(OH)2|C03]) and rosasite (CuZn[(OH)2| to that of rosasite, which is triclinic after CO3]) belong to it. Among them, only kolw Deliens and Piret (1980). A preliminary calcu ezite has the unequivocally determined symme lation of the present pattern yields larger try, which is triclinic (Deliens and Piret, 1980). differences between observed and calculated d The pattern of jamborite is indexed on a values even if the revised monoclinic cell (Jam hexagonal cell with a smaller c- and slightly bor, 1976) is referred to. Therefore, it is likely larger a-dimensions than the original material. that the present material is triclinic, although The chemical data inform the dominant occupa the indexing of the obtained pattern could not tion of (OH) or (OH+O) in the material, or be satisfactorily made. The same relation is lower SO3 (or S) content, which is involved in also found in mcguinessite, which is a the original material (Morandi and Dalrio, compositional intermediate between malachite 1973). An unnamed hydroxide of Ni by Jam and pokrovskite, both being monoclinic. The bor and Boyle (1964) has a=3.07A and c= real symmetry of mcguinessite will be lower 22.74A, and will be identified as jamborite. As than that of malachite or pokrovskite. In the compared with them, the a dimension of the original description on mcguinessite the authors present material is slightly different from it. have pointed out the possibility of lower sym This may be due to the vicarious presence of Fe metry (Erd et al., 1981). There are four basic to Ni, although the valency state of Fe is un carbonates of copper and divalent cations with determinable after the currently employed the general formula CuM2+[(OH)2|CO3]. method of chemical analysis. Mcguinessite (CuMg[(OH)2|CO3]), kolwezite (CuCo[(OH)2|CO3]), glaukosphaerite (CuNi Acknowledgements : We thank Mr. To- 524 Satoshi MATSUBARA and Akira KATO

shiaki Kamiya for his donation of a part of the hydroxide mineral from Rock Creek, British studied materials. Also, the present study has Columbia. Can. Mineral., 8, 116-120. Kato, A. and Matsubara, S. (1971), Tenorite from been financially supported by a Grant-in-Aid the Nakauri mine, Aichi Prefecture. Chigaku for Scientific Research of Ministry of Educa Kenkyu, 22, 410-412 (in Japanese). tion, Science and Culture to A. K. (No. Kohls, D. W. and Rodda J. L. (1966), Gaspeite, (Ni, 03403011). Mg, Fe) (CO,), a new carbonate from the Gasp Peninsula, Quebec. Amer. Mineral., 51,

677-684. References Matsubara, S. and Kato, A. (1979), The occurrence Deliens, M. (1975), La glaukosphaerite de of heazlewoodite and cobaltpentlandite from Kasompi (Shaba meridional, Zaire), Bull. the Nakauri mine, Aichi prefecture, Japan. Soc. Franc. Miner, Grist., 98,175-178. Mem. Natn. Sci. Museum, No. 12, 3-12. Deliens, M. et Piret, P. (1980), La kolwezite, un Morandi, N. and Dalrio, S. (1973), Jamborite: a hydroxycarbonate de cuivre et de cobalt ana new nickel hydroxide mineral from the north logue a la glaukosphaerite et a la rosasite. ern Appenines, Italy. Amer. Mineral., 58, Bull. miner., 103, 179-184. 835-839. Erd, R.C., Cesbron, F. P., Goff, F.E., and Clark, J. R. Suzuki, J., Ito, M. and Sugiura, T. (1976), A new (1981), McGuinessite, a new carbonate from copper sulfate-carbonate hydroxide hydrate California. Miner. Record., 12, 143-147. mineral, (Mn, Ni, Cu)8(S04)4(CO3)(OH)6•E Jambor, J. L. (1976), A possible unit cell for glau 48H2O from Nakauri, Aichi Prefecture, Japan. kosphaerite. Can. Mineral, 14, 574-576. J. Miner. Petr Econ. Geol., 71, 183-192. Jambor, J. L. and Boyle, R.W. (1964), A nickel

愛 知 県 新 城 市 産 蛇 紋 岩 中 のgaspeite, glaukosphaerite mcguinessiteお よ びjamborite

松 原 聰 ・加藤 昭

愛 知 県 新 城 市 中 宇 利 鉱 山 の 旧 坑 か らgaspeite, glaukosphaerite, mcguinessixeよ びjamboriteを 発 見 した 。Jamboriteは 鉱 山 付 近 の 瓶 割 峠 の 採 石 場 か ら も発 見 さ れ た 。GaspeiteはCo/(Ni+Co)=0.28～0.31, glaukosphaeriteはNi/(Ni+Cu)=0.42～0.49., CoO 5%(重 量)程 度 ま で 含 む 。 こ れ らの 種 で は 含Co変 種 は 最 初 の 発 晃 で あ る。Mcguinessite中 で はMg/(Cu+Mg)=0.61～0.65で 原 記 載 よ り高 い 値 を 示 す 。瓶 割 峠 産 のJamboriteはFe/(Fe+Ni)=0.29～0.32で,化 学 組 成 変 化 をFeに 富 む 側 に 拡 げ て い る 。これ ら は す べ て 蛇 紋 岩 を切 る 割 目に 着 生 す る皮 腰 を な し,成 因 的 に 循 環 地 表 水 と 関 係 が あ る。 こ れ ら の 中 の 金 属 元 素 は そ の 起 源 を皮 膜 下 の 含Ni蛇 紋 石, heazlewoodite, cobaltpendand量teお よ びdjurleiteに よ っ て い る よ うに 見 え る 。 これ ら の 炭 酸 塩 中 で のNi2+に 対 す るCo2+の 置 換 関 係 は こ の よ う な 固 溶 体 が 容 易 に 生 成 され る旧坑内の条件下での地球化学的挙動の類似性を暗示 している。