A collector's guide to Shijiangshan Mine, China: its geology, mining history and notable minerals, illustrated with the 55 specimens documented from this locality on EarthWonders.
Key facts
Shijiangshan is one of the defining modern rare-borate localities: a Pb-Zn-Ag skarn system in Inner Mongolia whose specimens changed the collector’s idea of what several obscure boron minerals could look like. Rather than yielding only microscopic reference material, the mine produced display-quality olshanskyite, roweite, pentahydroborite, borcarite, bultfonteinite, imayoshiite, datolite, and associated garnet-skarn minerals in hand specimens. Its best pieces have the visual language of a highly evolved, boron-rich skarn pocket: creamy to orange-brown lamellar roweite on snow-white to colorless olshanskyite; pale purple, gray, or white botryoidal datolite over calcite and garnet; fibrous bultfonteinite and shinichengite coatings; and sharp yellow-green to brown andradite providing the skarn matrix.
The mine is also scientifically important. Shijiangshanite, Pb3CaAl(Si5O14)(OH)3·3H2O, was approved as a new mineral in 2022 and named for the mine. Shinichengite, Ca5[BSi2O7(OH)2]2·6H2O, followed in 2023 as a second type-locality mineral. The locality has also furnished a high-symmetry sulfate-rich imayoshiite, a mineral previously known only from Japan, and it continues to be cited as one of the world’s strongest localities for well-crystallized rare borates.
Regional View
Country View
Collectors often encounter Shijiangshan under older or shortened labels: “Linxi,” “Yinwu,” “Shijiangshan-Shalonggou,” “Shijiang mine,” “Dashishan mine,” or even, on earlier borcarite material, “Huanggang.” The modern locality usage places the mine in Hexigten Banner, Chifeng City, Inner Mongolia, very near the Linxi county boundary; that boundary confusion explains much of the older label drift. For specimen purposes, the essential point is not the county line but the deposit style: this is a boron-rich skarn and late hydrothermal pocket locality associated with the broader Huanggangliang mineralized district, not merely another generic Inner Mongolian fluorite or quartz source.
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Shijiangshan is a polymetallic Pb-Zn-Ag deposit developed in the southern Greater Hinggan region of Inner Mongolia, within the Tuquan-Linxi metallogenic belt and close to the famous Huanggangliang mineralized district. Published descriptions identify it as a skarn-type Pb-Zn mine with unusually boron-rich late mineralization, although ore studies of the No. 1 vein also describe hydrothermal vein-style fracture filling. The deposit sits in a complex intrusive and volcanic-sedimentary terrane: Permian units in and around the district include slate, metamorphosed siltstone, tuffaceous rocks, sandstone, limestone, and dolomite, with Yanshanian granitic intrusions and granite-porphyry or quartz veins providing the magmatic-hydrothermal driver.
The economic ore is dominated by galena, sphalerite, arsenopyrite, chalcopyrite, and pyrite, with quartz and calcite as important gangue in the sulfide vein system. One ore study of eight underground samples from the No. 1 Pb-Zn vein found silver mainly in invisible forms: submicron tetrahedrite-dyscrasite inclusions in sulfides, especially pyrite, and lattice-bound silver in galena. Channel-sample grades cited for that vein reached Ag 248.88 g/t, CuO 0.383%, Pb 3.996%, and Zn 3.598%, with an average orebody thickness of about 1.1 m. Later locality summaries cite substantial lead and zinc resources and ten identified orebodies, with lens-shaped and vein-like ore bodies controlled by faulting and skarn contacts.
The skarn assemblage is the collector’s key to Shijiangshan. Ore and gangue occur as garnet-skarn, diopside-skarn, epidote-skarn, and quartz-vein material. The broader paragenesis is generally described in three stages: an early prograde stage with anhydrous silicates such as diopside, garnet, and wollastonite; a retrograde stage with hydrous silicates including actinolite, amphibole, and epidote, accompanied by magnetite deposition; and a quartz-sulfide stage that represents the main metallogenic event. The rare borates and highly hydrated Ca-silicate or Ca-borosilicate species beloved by collectors belong to late, low-temperature hydrothermal pockets in and around the skarn, where boron, carbonate, fluorine, arsenic, and very alkaline fluids produced a mineral suite far richer than the usual Pb-Zn ore assemblage.
Mining is reported to have begun in 2008, and the mine has been treated in recent locality databases as active, though published scientific work around 2016 also described parts of the district as being in a prospecting and study stage. The specimen-producing zones appear to have been episodic rather than continuously productive. Early Western market awareness centered on pentahydroborite and borcarite around 2014; exceptionally good roweite and olshanskyite pieces were being sold from 2017 material; and a 2021 pocket produced bultfonteinite, imayoshiite, and material later recognized as shinichengite. Later specimens of shijiangshanite from 2024 showed red-orange to colorless crystals on calcite and andradite, and high-quality datolite-imayoshiite-bultfonteinite assemblages continued to appear in small numbers.
Collecting access today should be regarded as closed to casual visitors. This is an operating or recently operating Chinese mine, not a public collecting site, and the best specimens have reached collectors through Chinese suppliers and specialist dealers rather than field collecting by hobbyists. Several dealer accounts specify that particular specimen-producing pockets or spots have been covered, closed, or mined through. The result is a market with periodic small releases, strong demand from rare-species collectors, and a premium on specimens with reliable documentation and analytical confirmation.
Datolite from Shijiangshan is one of the locality’s quieter but most diagnostic collector minerals, typically appearing as pale purple, gray, white, or colorless globular to botryoidal crystallized masses rather than the isolated sharp crystals of many classic skarns. It is closely tied to the late boron-rich pocket assemblage and is repeatedly documented with andradite, bultfonteinite, imayoshiite, hydroxyapophyllite-(K), calcite, and, in some analyzed material, bakerite-like datolite-group compositions. Good pieces show clean, continuous botryoidal coverage or glassy colorless datolite associated with rare species; ordinary pieces are more massive, patchy, or overgrown by fibrous coatings. The strongest Shijiangshan datolites are not valued merely as datolite specimens but as matrix-forming parts of highly evolved rare-mineral associations, especially when pale botryoidal datolite contrasts with yellow-green andradite or carries imayoshiite and bultfonteinite on top.
Andradite is the principal garnet of the Shijiangshan skarn assemblage and the visual anchor for many of the mine’s rare-borate specimens. It ranges from yellow and yellow-green to brownish tones, occurring as massive garnet-skarn, small sharp crystals, and drusy or granular surfaces associated with olshanskyite, roweite, pentahydroborite, datolite, bultfonteinite, calcite, galena, wurtzite, magnetite, and shijiangshanite. The most collectible andradite-bearing pieces are those in which the garnet gives structure and color to the specimen without overwhelming the rarities: lime-green or yellow-brown crystals under red-orange shijiangshanite, small garnets sprinkled through white olshanskyite, or discrete andradites accompanying lamellar roweite. Pure andradite specimens are less central to the locality’s reputation than association pieces, but the garnet is essential evidence of the skarn environment that made the rare borate suite possible.
Shijiangshan is a world-class locality for olshanskyite, and its best crystals are dramatically better than the species was once expected to produce. The mineral occurs as colorless to cloudy white, transparent to translucent, long prismatic, well-terminated crystals, often in radial aggregates or crystal sprays with roweite, andradite, magnetite, wurtzite, galena, calcite, and occasionally johnbaumite. Published analytical work on Shijiangshan material verified olshanskyite by X-ray diffraction and thermal behavior after Raman spectra initially raised doubts, and studied crystals ranged from millimeters to as much as 4 cm, with 1.5 cm crystals illustrated as already exceptional. Collector-grade examples emphasize sharpness, transparency, silky-to-vitreous luster, and freedom from bruising; the finest pieces combine colorless lustrous olshanskyite sprays with contrasting cream to brown-orange roweite and a stable garnet-rich matrix.
Roweite from Shijiangshan is among the locality’s trophy species, occurring as pale orange-brown, tan, cream, or light brown lamellar to tabular orthorhombic crystals, commonly in rosettes, leafy aggregates, or spear-like forms perched on olshanskyite-rich matrix. Dealer and show records describe individual roweite crystals to about 1.4 x 1.3 cm and even 2.2 x 1.4 cm on larger matrix pieces, while other accounts cite transparent to translucent spear-shaped crystals to 1.5 cm—extraordinary dimensions for a species once essentially a Franklin rarity. The best Shijiangshan roweites are sharply separated, lustrous, translucent at the edges, and aesthetically associated with colorless olshanskyite; lesser pieces are more massive, contacted, or visually lost in mixed pale matrix. Because the main productive zone appears to have been mined through, fine roweite-olshanskyite associations are much less routinely available than when the 2017 material first circulated.
Calcite at Shijiangshan is chiefly important as gangue, pocket matrix, and a contrasting white host for rare species rather than as a standalone calcite locality. It occurs in ore veins and skarn pockets, including cleavages or white matrix surfaces associated with bultfonteinite, shinichengite, datolite, andradite, shijiangshanite, and imayoshiite. In specimen descriptions it commonly appears as white calcite matrix beneath orange-brown bultfonteinite spheres or fibrous shinichengite coatings, and as a clean background for pink to red-orange shijiangshanite crystals; some shijiangshanite-bearing specimens also show calcite fluorescence under long-wave UV while andradite remains dark. Good calcite-bearing Shijiangshan specimens are judged by how well the calcite supports and frames the rare species—solid, bright, and not overly cleaved or bruised—rather than by calcite crystal size or form.
Beyond those five species, Shijiangshan has become a reference locality for a remarkable late skarn rare-mineral suite. The type-locality minerals are shijiangshanite, a pale pink to red layered silicate related to wickenburgite, and shinichengite, a pale pink hydrated borosilicate chemically related to oyelite. Other documented or market-significant minerals include imayoshiite, bultfonteinite, pentahydroborite, borcarite, cahnite, johnbaumite, bakerite, hydroxyapophyllite-(K), fluorapophyllite-(K), tobermorite-group minerals, vesuvianite, wiluite, prehnite, diopside, grossular, axinite-(Fe), cuspidine, nifontovite, fluorapatite, magnetite, galena, sphalerite, wurtzite, arsenopyrite, chalcopyrite, pyrite, and quartz. For rare-species collectors, the most important lesson is that Shijiangshan pieces should not be identified by sight alone: several of the visually similar white, colorless, fibrous, bladed, or botryoidal calcium borates and hydrated calcium silicates require XRD, Raman, SEM-EDS, or single-crystal work for confident naming.
The central authenticity issue at Shijiangshan is not outright fakery so much as misidentification and label drift. The locality has produced many pale, hydrated calcium borates and Ca-silicate species that can look deceptively similar in hand specimen, and some are poor candidates for simple SEM-EDS identification because boron is difficult to measure by routine EDS. Olshanskyite provides the cautionary example: analytical work on Chinese material confirmed genuine Shijiangshan olshanskyite, but the same study noted that many specimens circulating elsewhere under the olshanskyite name proved to be other calcium borates such as hexahydroborite, calciborite, or uralborite. For expensive olshanskyite, roweite, imayoshiite, shinichengite, shijiangshanite, or unusual datolite/bakerite pieces, an analysis note from a credible laboratory or dealer is not a luxury; it is part of the specimen.
Older locality labels need scrutiny. “Linxi” is common and historically understandable, but current locality usage places the mine just outside the Linxi boundary in Hexigten Banner. “Shijiangshan-Shalonggou” and “Shijiang mine” may appear on early imayoshiite or borate labels, and early pale green borcarite with cahnite was reportedly attributed to Huanggang before Shijiangshan was recognized as the proper source. A vague “Huanggang” label on rare borates should therefore be treated with caution and compared against the specific Shijiangshan paragenesis.
Condition is another major concern. Olshanskyite and roweite crystals are often on uneven skarn matrix and may project as delicate blades, tablets, or sprays; edge chipping, contacted backs, and broken terminations are common. Fibrous bultfonteinite, shinichengite coatings, and botryoidal datolite can be fragile or powdery at the surface, and calcite-cleavage matrices can bruise or detach if handled roughly. Avoid ultrasonic cleaning, acids, aggressive water soaking, and repeated handling. Highly hydrated minerals such as imayoshiite and shinichengite should be stored in a stable indoor environment away from heat, strong sunlight, and very dry display cases.
Fluorescence can be useful but should not be treated as identification. Some shijiangshanite has been reported to show deep red fluorescence under 365 nm long-wave UV, while associated white calcite may fluoresce white and andradite may remain inert. That response can help document a specimen visually, but it does not distinguish every red, pink, or fibrous Shijiangshan phase.
Market availability is uneven. The locality is well represented in recent rare-mineral trade, but the best roweite-olshanskyite and olshanskyite specimens were more available during earlier releases than they are now. Dealer reports indicate that some specific productive spots are closed, covered, or mined past. Small datolite, bultfonteinite, imayoshiite, and association specimens still appear periodically, while large, sharp, analyzed roweite-olshanskyite combinations and type-locality shijiangshanite or shinichengite specimens command a stronger premium.
The Shijiangshan story entered the Western collector market almost as a puzzle. Around 2014, specimens of pale green borcarite sprinkled with tiny cahnite crystals had been circulating under the glamorous shadow of nearby Huanggang. Then pentahydroborite appeared from Shijiangshan itself: colorless to milky, triclinic crystals standing at high angles from matrix plates 6 cm to more than 10 cm across, accompanied by microcrystals of andradite, galena, and wurtzite. At the time, even experienced observers were still trying to place the mine within the broader Huanggang mineral province, and the realization that Shijiangshan—not Huanggang—was the source of the borcarite shifted attention to a smaller, stranger Pb-Zn skarn with a chemistry of its own.
The olshanskyite episode is a rare-species collector’s morality tale. The Shijiangshan crystals looked almost too good: transparent to white, well formed, and in some cases reaching centimeter size, far beyond the modest expectations for the species. Before the material was confidently accepted, samples were checked by Raman spectroscopy, chosen because it is quick, nondestructive, and well suited to borates. The first surprise was unsettling: the Raman spectrum did not match published reference data. For a moment the question was whether Shijiangshan had produced something new. XRD and thermal work then showed that the Chinese crystals were indeed olshanskyite, while the reference problem pointed in the opposite direction—some earlier “olshanskyite” material used for published spectra was apparently not olshanskyite at all. The practical lesson was blunt: a rare borate label, even when attached to an exciting specimen, is only as good as the analytical work behind it.
The 2021 bultfonteinite-shinichengite material added a second kind of surprise. Dealers first described the pink fibrous coatings as possible tobermorite-clinotobermorite, a reasonable field guess for a pale, hydrated calcium silicate-looking mineral on calcite, andradite, and bultfonteinite. Later study showed that the pink coatings belonged to a new borosilicate species, shinichengite, approved in 2023 and named for Chinese mineralogist Shi Nicheng. Some specimens had already been sold or cataloged under the earlier tentative identification, which means careful collectors now prize the older 2021 labels and accompanying analyses because they document the transition from field identity to type-locality mineral.
Shijiangshanite made the mine’s name literal. Approved in 2022, the mineral was named for the Shijiangshan Pb-Zn mining area and became the first new species described from the locality. Its occurrence—pale pink to red, in stacked tabular or crust-like aggregates on calcite and garnet-skarn matrix—gave collectors a visually distinctive type-locality species rather than a purely microscopic curiosity. Later 2024 specimens with red-orange shijiangshanite on white calcite and yellow-brown andradite showed that the locality could still produce fresh surprises after the famous olshanskyite-roweite period.
