"Rock of the Month #137, posted for November 2012" ---

Stibnite, ideal formula Sb₂S₃, is the principal ore mineral of antimony (Sb), element 51. Fine specimens have long been recovered from mines in Japan, also from Romania, and most recently from China.

The Herja mine is located near the village of Chiuzbaia (formerly Kisbanya), southwest of Baia Mare in the region of Transylvania, northwest Romania, abutting Ukraine and Hungary. This gold and antimony mining district has also produced the iron- antimony sulphide berthierite (Buerger and Hahn, 1955; Oelsner, 1961). A spectacular specimen of coarse, purple-tarnished needles of berthierite with calcite, stibnite and jamesonite, which I viewed in 1999 in the systematic collection of the Natural History Museum in London, is attributed to the locality of Chiuzbaia. Stibnite is well-represented in museums in eastern Europe (Bancroft, 1988). Romanian stibnite samples are also reported from Maramures (Cooper, 1995), which lies east of Baia Mare on the east-west border against Ukraine to the north. Romania has also yielded samples of tellurantimony, natural Sb₂Te₃ (Simon et al., 1995) as well as oxidized, secondary Sb mineral species. Native gold, tellurides and other minerals are known throughout the wider region, which is endowed with various porphyry, skarn and vein deposits, and which has been mined at least since Roman times, for 2,000 years or more. In the context of superior mineral samples, Pagano (2007) warned about fake specimens purported to be from Romania, such as stibnite crystals from China glued onto a Romanian matrix material, synthetic potassium dichromate sold as realgar, and calcites dyed to resemble rhodochrosite.

Stibnite is a familiar ore mineral in museums, especially due to the spectacular samples from Japan, which have been available for many years. It is sparsely but widely distributed, mostly in mesothermal to epithermal mineral deposits, and is widely reported (>420 records in the MINLIB bibliography, October 2012).

In recent years China has come to dominate world antimony production. The country is thought to have 50% of world reserves of Sb and accounts for 80% of Sb production (Behling et al., 2002). The main producers are from the huge deposits of Hunan, but at least 12 other regions of China also have mesothermal to epithermal Sb deposits. Fine specimens of stibnite have also emerged. Crystals exceeding 50 cm in length were recovered in late 2000 from the Wuling (Qingjiang) mine (Behling et al., 2002). Other Chinese sources of fine specimens have emerged, and are reviewed by Ottens (2007). Fine specimens of stibnite and stibiconite are recovered at what is now the world's largest antimony mine, the Xikuangshan Sb mine in Hunan (Liu et al., 2013, pp.56-57).

In north America, stibnite occurrences with fine crystals exist in California (Dunning and Cooper, 1989) and Nevada.

References

Bancroft,P (1988) Mineral museums of Eastern Europe. Mineral.Record 19 no.1, 1-52.

Behling,SC, Liu,G and Wilson,WE (2002) Stibnite from the Wuling antimony mine, Jiangxi province, China. Mineral.Record 33, 139-147.

Buerger,MJ and Hahn,T (1955) The crystal structure of berthierite, FeSb₂S₄. Amer.Mineral. 40, 226-238.

Cooper,MP (1995) Munich show 1994. Mineral.Record 26, 141-146.

Dunning,GE and Cooper,JF (1989) Stibnites of the Stayton district, Hollister, California. Mineral.Record 20 no.6, 427-438.

Liu,G, Lavinsky,RM, Meieran,ES, Schmitt,HH, Moore,TP and Wilson,WE (2013) Crystalline Treasures: the Mineral Heritage of China. Mineral.Record 44, supplement, 104pp., January.

Oelsner,O (1961) Atlas of the Most Important Ore Mineral Parageneses under the Microscope. Pergamon Press (translated by Hazzard,BJ, edited by Howie,RA), 311pp.

Ottens,B (2007) Chinese stibnite: Xikuangshan, Lushi, Wuning and other localities. Mineral.Record 38, 3-17.

Pagano,R (2007) Torino show 2006. Mineral.Record 38, 151-154.

Simon,G, Alderton,DHM, Stumpfl,EF and Bleser,T (1995) Tellurantimony in Romania: first occurrences in Europe. Mineral.Petrol. 53, 115-124.

Natural History Museum, London, England, 13 November 2012.

Case 11 of the systematic collection features stibnite. 28 pieces were on display on this date. There was also a metastibnite, the amorphous form of the mineral, crudely botryoidal, with pyrite and galena, from Pulacayo, Bolivia. One mass of brilliant coarse laths of stibnite, with a secondary generation of smaller prisms growing in diverse orientations off the main aligned mass, circa 15x6x4 cm, is from Herja Chiuzbaia, the same area and quite possibly the same mine as this Rock of the Month. The largest stibnites were, not surprisingly, from the famed site of Ichinokawa, Japan: the two largest pieces are in a nearby display case. Another spectacular piece is from Bau (Sarawak, Borneo).