Ichinokawa Mine, Japan — stibnite famed for large prismatic crystals, metallic luster, and historic Meiji-era provenance; a landmark locality for collectors.
Key facts
Ichinokawa is the old master of stibnite localities: the Japanese mine whose great metallic prisms set the visual standard by which most other stibnite is still judged. The classic crystals are not merely long; they are thick, sculptural, and architectural, with ribbed faces, chisel-like to complex terminations, a lead-gray to bluish-black metallic luster, and a presence that feels closer to forged steel than to a sulfide mineral. Fine pieces have the combination collectors want most from this locality: substantial individual crystals, sharp longitudinal striation, bright unpowdered surfaces, minimal bruising, and a convincing old provenance.
Photo: James St. John / Wikimedia Commons
The mine lay in what is now Saijō City, Ehime Prefecture, on Shikoku. Its ore was antimony, and its fame came from stibnite, Sb2S3, formed in quartz-stibnite veins cutting crystalline schist and the Ichinokawa conglomerate. The collector-grade crystals developed in open pockets within the veins, where the mineral could grow freely rather than as massive ore. That pocket growth is the key to the locality’s distinctive look: large prismatic crystals, commonly grouped in bundles, with projecting needle-like and blade-like forms that create the dramatic “clustered timber” effect praised in Japanese mineral literature as early as the eighteenth century.
Ichinokawa is also unusually important historically. Its antimony was tied to Japanese mining and metallurgy from early historical tradition through the Edo, Meiji, Taishō, and Shōwa periods. The mine’s greatest mineral-specimen fame belongs especially to the Meiji era, when crystals were shown at international exhibitions and exported into major museum collections. Today, important Ichinokawa stibnites are held by Japanese institutions and by museums across Europe, North America, and Australia; the large, old, undamaged groups are effectively heritage objects.
Photo: Rob Lavinsky, iRocks.com / Wikimedia Commons
For serious collectors, the attraction is threefold. First is aesthetics: the best crystals have a solemn, metallic grandeur unlike the hairier, more acicular modern Chinese material. Second is historical status: an Ichinokawa label connects a specimen to one of the foundational classic localities of mineral collecting. Third is scarcity: the mine has been closed since 1957, and most fine specimens entered museums or old private collections generations ago.
Search for specimens: View all stibnite specimens from Ichinokawa Mine, Japan
Ichinokawa Mine was an antimony mine in the Ichinokawa district of Saijō City, Ehime Prefecture. Geologically, the deposit belongs to the belt of antimony occurrences associated with the Median Tectonic Line region of Shikoku, and its ore bodies were quartz-stibnite veins hosted in crystalline schist and Ichinokawa conglomerate. The country rock is described locally as graphite schist and related Sanbagawa metamorphic rocks, with vein development along fractured and brecciated zones. The ore was not a single simple lode but a network of veins and adits in the Maruno River valley area.
The vein system included steeply inclined “vertical” veins and lower-angle “horizontal” veins. The principal steep veins were traditionally grouped into northern veins such as Taisei, Senga, and Saiwai, and southern veins such as Tsuru, Kame, and Noboritate. The horizontal vein system on the north side of the river included Tenjo-hi, Naka-hi, and Sui-hi. Individual veins were commonly 20 cm to 1 m wide, narrowing and swelling along strike, and were reported to range from about 200 m to as much as 1,000 m in length. Within these veins, cavities developed in quartz and stibnite; those open spaces produced the famous free-grown crystals.
The mine’s recorded history is deep and tangled. Local tradition and historical interpretation connect Iyo antimony with early Japanese records, but the better documented rediscovery belongs to the early Edo period. In 1679, Chikanobu Sogabe, a village headman of Ohama, is said to have found an outcrop while repairing a road near Hotoke-ga-tōge, and development followed. Edo-period operations were modest and intermittent, with smelting difficulties and fluctuating antimony prices repeatedly interrupting mining. Under Komatsu Domain management in the nineteenth century, records show organized production, wages, rice stipends, and continuing attempts to make the mine economically reliable.
Ichinokawa’s great specimen fame rose in the Meiji period. Stibnite crystals from the mine were displayed at the Kyoto Exhibition in 1871 and at the Paris World’s Fair in 1878, where they received silver medals. Later appearances at domestic and international exhibitions helped make the locality known outside Japan. During the boom from about 1882 to 1897, Saijō City records credit the mine with producing roughly half of Japan’s annual antimony output in some years. From 1875 to 1957, official local figures give 36,700 tonnes of concentrate and 19,000 tonnes of antimony metal content.
The mine’s history was not orderly. In the early Meiji years, its success triggered a rush of applications, disputes, fraudulent claims, and claim-jumping around the mineral rights. These conflicts became notorious enough to be remembered as the “Oyama Sōdō,” the mountain dispute. Government intervention in the 1880s eventually brought the competing claims under control, and rights were returned to a group of former stakeholders in 1889.
A second period of prosperity came during World War I, when antimony was strategically important for military alloys. The mine company installed a hydroelectric plant at Gomahara in 1915, added winches, drainage pumps, ore-separation equipment, and improved smelting furnaces, and planned a major expansion. This Taishō-era boom ended quickly after the war economy changed; the Doba refinery stopped around 1918, and the mine’s last great period with hundreds of workers was over.
Later Shōwa operations were smaller. Work resumed in the late 1920s and early 1930s under Takehei Ito and Fusakichi Takahashi, with hand mining over a broad area. Sumitomo Metal Mining acquired the property after World War II. Operations were suspended in 1947, restarted in 1951, mechanized exploratory adits were driven from 1954, and mining ceased in May 1957. The mine has remained closed.
Collecting access should be treated as closed and hazardous. Saijō City specifically warns against entering the Senga adit area because of collapse danger, and old workings in the district include unnamed portals and vertical openings. The locality is historically and culturally significant, and any visit must be approached as a heritage-site visit, not as an collecting opportunity.
The iconic Ichinokawa crystal is a thick, longitudinally striated prism with a bright metallic gray to bluish-gray luster and a complex, often chisel-like termination. Many specimens show parallel to subparallel growth: several prisms rising together, intergrown like a bundle of dark steel laths. Others occur as single crystals, sometimes slightly curved or bent, reflecting stibnite’s well-known flexibility and glide behavior. The most desirable examples balance mass and elegance: not just a long needle, but a robust, sculptural crystal with intact faces and a natural termination.
Large crystals are central to the locality’s reputation. Historical sources describe individual crystals reaching about 90 cm, and Mineralogical Record authors and older collectors repeatedly emphasize groups in the 20-inch class. Cabinet specimens in the 7–15 cm range are much more realistic on the market, while 20–40 cm examples are major pieces and larger historic groups are essentially museum-level. Even small Ichinokawa crystals can be important when they show the right locality style: strong striation, metallic luster, thick proportions, and old labels.
Color is usually silvery lead-gray, steel-gray, blue-gray, or darker gray-black where surfaces have oxidized or tarnished. A delicate bluish iridescent patina is known on some fine pieces and can add character, provided it is natural and not a dull, powdery alteration. Fresh fractures and rubbed points may look brighter silver-gray; old exposed surfaces can darken.
Associated minerals are limited but important. Quartz is the principal gangue and the most common specimen association. Calcite is recorded from the mine, along with minor pyrite and arsenopyrite in the ore assemblage. Secondary antimony minerals recorded from the locality include stibiconite and valentinite. Cinnabar, magnesite, coquandite, and klebelsbergite are also listed for the broader Ichinokawa locality, but classic collector specimens are overwhelmingly judged as stibnite specimens, with quartz association being the main matrix feature.
Quality factors are unforgiving. Ichinokawa stibnite is soft, brittle, and readily cleaved, so perfect terminations, undamaged edges, and unrepaired large crystals are rare. Many old specimens have edge bruising, contacted backs, repaired bases, or scattered microscopic chips. Collectors should judge condition relative to the locality rather than by unrealistic standards: a large, lustrous, terminated Ichinokawa crystal with only minor edge wear can be far better than an apparently “perfect” but thin, less characteristic piece from a modern locality.
The best examples differ from many modern Chinese stibnites by their heft and historical morphology. Chinese specimens can be spectacularly large and brilliant, but Ichinokawa classics often have a thicker, more columnar, old-time architecture, with bolder prismatic faces and a subdued metallic dignity. Provenance, label history, and credible locality attribution are therefore part of the specimen’s character, not merely paperwork.
Authentic Ichinokawa stibnite is scarce because the mine is long closed and most significant specimens were collected in the late nineteenth and early twentieth centuries. The market is therefore dominated by old-collection pieces: single crystals, partial crystal groups, and occasional larger cabinet specimens that surface from estate collections, European dealer stock, Japanese collections, or museum deaccession history. Freshly collected Ichinokawa material should be treated with skepticism unless the provenance is exceptionally clear.
The most common authenticity issue is misattribution rather than outright fabrication. Stibnite from China, Romania, Italy, or other localities may be offered simply as “Japanese” or may acquire an Ichinokawa attribution because it has thick crystals or an old look. A convincing Ichinokawa specimen should match the locality style and ideally carry supporting labels or a collection history. Old labels from Japanese, European, or American collections add substantial confidence, especially when the specimen itself shows the robust, striated, steel-gray habit expected from the locality.
No well-documented, locality-specific treatment tradition is associated with Ichinokawa stibnite in the way that some gem minerals have known enhancement practices. That said, repairs are common enough to be expected on larger stibnite from any classic locality. Look carefully for glued terminations, reattached crystals, filled cracks, dark adhesive along contacts, and base repairs concealed by old matrix or mounting material. Because stibnite has perfect cleavage and a low hardness, an apparently dramatic “termination” can sometimes be a cleaved or worn end rather than a natural growth termination.
Condition issues are central. Stibnite is soft enough to scratch easily, fragile enough to bruise along edges, and chemically prone to dulling or darkening with long exposure to air and light. Ichinokawa crystals should be handled as little as possible, never cleaned aggressively, and never scrubbed. Dust removal is safest with a very soft air bulb or the lightest possible brush, avoiding pressure on terminations and crystal edges. The mineral contains antimony; normal display handling is not usually the principal concern, but avoid inhaling dust, licking or wet-cleaning the specimen, or allowing children to handle it.
Display requires restraint. Strong direct light can emphasize metallic luster, but prolonged bright light and open-air exposure may accelerate dulling. The Saijō City Local History Museum keeps a major Ichinokawa specimen in a sealed case because of oxidation concerns. For a private cabinet, a stable, dry, closed display case is preferable to an open shelf. Support the specimen securely; long single crystals are especially vulnerable to snapping if a base shifts.
In the present market, small to mid-sized Ichinokawa singles and clusters appear occasionally, while large, undamaged, aesthetic groups are rare and heavily competed for. A specimen with old labels, clear provenance, strong luster, a natural termination, and minimal repairs belongs in the upper tier even at modest size. A specimen with a vague locality, dull altered surfaces, major glue work, or broken ends should be priced and described accordingly.
The best Ichinokawa stories begin in darkness, with sound. Former miner Yazo Yano, who started work at the mine in 1893, remembered that the stibnite cavities could be detected because they were hollow enough to echo the footsteps of passing miners. A pocket was not simply seen; it was heard. Once located, it had to be opened with extraordinary patience. The skilled chisel workers dug perhaps 90 cm around a large crystal to free it without breaking it, and the great crystals were treated almost as living things. Miners said that a crystal inside the cavity was “still growing,” a phrase that captures both the softness they perceived and the caution the work demanded.
The mining methods explain why Ichinokawa produced crystals that survived at all. Before mechanized drilling, miners worked with hammer and chisel, and hard rock was sometimes heated with charcoal. In the Meiji period they used gunpowder, but the charge was crude and modest compared with dynamite: a chisel hole about 60 cm deep was packed with grain-sized pellets and fired with a fuse. Yano believed the celebrated 90 cm crystal recovered in 1880 was taken out by hand with a tagane chisel. Had the mine relied from the beginning on boring machines and powerful explosives, many of the famous crystals would likely have been reduced to ore.
The lamps were just as vivid as the crystals. When Yano began, miners still used seashell lamps filled with rapeseed oil, probably turban shells, with cotton wicks. Iron lamps were also used, and acetylene lamps came later. The old work song “Settobushi” mocked third-class miners by saying hand lamps were too good for them: “Let’s buy them some turban shells.” That single line preserves a whole hierarchy of light underground, from a shell of oil to the better lamps carried by higher-status workers.
At the surface, the mine was not a lonely hole in the mountains but a boom settlement. In the Meiji golden age, the phrase “Shirome sengen,” the many houses of Ichinokawa, was used locally. Apprentices Ichitaro Bunno and Yazo Yano recalled at least 1,000 workers during that period. Two-story tenements about 18 meters long stepped up the slope near the mountain-god shrine. Fish markets, restaurants, bathhouses, theaters, geisha, and policemen all belonged to the mining landscape. People climbed up from Saijō early in the morning by lantern light, carrying lunches and searching in groups for antimony ore.
When a rich vein was struck, the event had its own phrase: “piercing a great vein.” The celebration could run for two or three days of drinking and singing. The mine also had work songs for miners, ore beaters, and the women who separated ore. When 30 or 40 voices sang together, the songs echoed through the adits and sorting places. Most of those songs are now lost, but the surviving lines name the places and pleasures of Saijō: Bujo’s cherry blossoms, Kannon-dō Temple, Tano-ya’s second floor, Kaga-ya’s udon, soba, and gomoku-meshi.
Sokichi Tokunaga, one of the bold Meiji managers, remains almost theatrical in the surviving anecdotes. In 1880 he donated a torii gate to Shiromeyama Shrine. He was remembered for lavish spending on geishas at Konpira in Kagawa Prefecture, for scattering money on the ground for geishas to pick up, and for donating 1,000 yen, a huge sum at the time. On a sales trip to Osaka, he tapped the rim of a silver brazier with the head of his tobacco pipe. When a shocked clerk scolded him, Tokunaga laughed: “Silver is cheap.” The performance worked; the clerk took him for a man of immense wealth, and negotiations moved in his favor.
The women’s work was exacting and physical. A yurifu-san, a female ore separator, wore karusan, a short hakama-like work garment, sat on a large cushion, and shook ore in a shallow round sifter over a waterproof cover on her knees. She lifted a basin from a tank of water about 1.2 square meters, separated stibnite from waste rock, placed the good mineral into a deep container, and then reworked the silt at the bottom. Other women, called kanametataki, broke ore from waste rock with hammers at huts near the adit entrances. The mine’s beauty in museum cases was built on countless repetitive motions like these.
The rewards could be real. In the 1930s, an average miner was expected to produce 3.75 kg of ore per day. Skilled miners might produce 187.5 to 225 kg in a month, and quota bonuses were paid in rice: 30 kg for more than 187.5 kg of production, 60 kg for more than 375 kg. A miner who produced 700 kg earned major rewards in both money and rice, with the rice brought down from the mountains on horseback. Tsurumatsu Ito remembered New Year’s raffle tickets, with prizes such as clocks, clothing, and jikatabi split-toed work shoes; he himself won an alarm clock.
But the human cost was severe. The former accounts describe pale miners, breathing disorders, and many widows. The booklet’s grim phrase that “99 in 100” miners died by age 50 almost certainly reflects the remembered burden of dust and lung disease, including silicosis. The adits themselves ranged from larger passages such as Senga-ko, about 2.5 m by 2.5 m, down to unnamed workings only about 90 cm by 1.2 m, where miners had to crouch and haul rock in boxes by ropes over their shoulders. In hand-driving hard rock, a shift might advance only 10 cm a day; after pneumatic drills arrived, the advance could exceed 1.5 m.
The closing image is almost elegiac. After operations ended in 1957, the mine office, sorting plants, machinery houses, storehouses, bathhouses, tenements, and guest house disappeared one after another. By the early 1980s, Isamu Ito of the Ichinokawa Community Center found the mine site covered in grass and earth, little remaining as it had been. His afterword insists that the mine should not disappear from both the earth and people’s memories. For collectors, that is part of what an Ichinokawa stibnite carries: not only a metallic crystal, but the sound of shell lamps, chisels, songs, and a vanished mountain town.
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