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Zhao Yanwei and Chen Baipeng (Song)
Song Yingxing (Ming, 1637)
Wu Qijun and Xu Jinsheng (1844)
Silver yields
The identification of ores

 

Very little is known on the types of silver ores that historic mines in China exploited. In fact, throughout the history of pre-industrial mining, the grand total of records that contain more than a passing mention amounts to five short passages. The first three of these are not referring to Yunnan, however, as the amount of material is minimal, they may be surveyed here as an introduction to the terminolorgy.

The first two texts date to the later Song and record mines in the mountains of northern Fujian and southern Zhejiang. The two authors, Zhao Yanwei 趙彦衛 (fl. 1163-1206) and Chen Baipeng 陳百朋 (fl. late 12th cent.) provide vivid and specific descriptions, but no detail on the ores.

Zhao Yanwei mentions “where black paths are found in the cliffs, these are silver veins” (毎石壁上有黒路乃銀脈，黒路乃銀脈) Zhao Yanwei 1998, juan 2, pp. 12, translated and discussed in Yang and Kim 2018, 19-20). Cheng Baipeng records:

唯於頑石中隱見礦脈，微如毫髮。有識礦者得之，鑿取烹試。其礦色樣不同，精粗亦異。礦中得銀，多少不定，或一籮重二十五斤，得銀多至二三兩，少或三四錢。

Where ore veins show in the dumb rock, these are fine as hairs. Those knowledgeable in ores obtain them, chisel them out and assay them. Ores vary in colour and thickness, and the silver content is also uncertain, varying between 2-3 liang per basket of 25 jin to only 3-4 qian. (Lu Rong 陸容 1985, 175).

The information on the types of ore is vague, while the yields convert to 7500-5000 g/t for the richer and 1000-750 g/t for the poorer ores, working with the standard jin of 16 liang. The ores worked in eastern China around 1200 were surprisingly low in silver content.

Song Yingxing’s 宋應星 (1587-1666) technological encyclopaedia Tiangong kaiwu 天工開物, which was first printed in 1637, differentiates four kinds of silver ores:

凡成銀者曰礁，至碎者曰砂、其面分丫若枝形者曰鉚，其外包環石塊曰礦。 ... 其礁砂形如煤炭底襯石而不甚黑，其高下有數等。

All that transforms into silver is called jiao 礁, very small granules are called sha 砂 (sand), that with twig-like branching shapes on the surface is called mao 鉚 (nails), and that which is enveloped in rock is called kuang 礦 (ore). The ore is similar in appearance to coal with a base of rock, yet not altogether black. It occurs in several grades of richness. (Song 1637, juan xia, p. 5a, transl. Yang and Kim 2018, 26)

According to our tentative interpretation based on the above quote and compound expressions used in this and other tests, such as jiaosha 礁砂 (charcoal rock and sand), jiao 礁 is the general term designating all silver ores and also the name of rich silver ore. As jiao commonly refers to coal, the name appears to indicate a black and shiny appearance, for which reason we suggest that the name may be identified as argentite or a comparably rich ore. Loose ore is called sha 砂 (sand, gravel), while mao 鉚 (nails) is a structured ore with visible “nails”, possibly andorite , and kuang 礦 (ore) a general term for lower grade ores, possibly galena. Song Yingxing provides no geographic information for his record (Yang and Kim 2018, 26).

In short, our entire knowledge on silver ores in China up to the 19^th century boils down a colour spectrum in which black ores might have been the richest and four technical terms, of which jiao 礁 is the only relatively identifiable one that designates rich, probably typically blackish and shiny silver ores.

The two latest sources contain relatively systematic classification of silver ores in Yunnan. They date to the 1830s to 1840s and probably specifically record conditions in the Kuangshan 礦山 mines in northeastern Yunnan. Diannan kuangchan tulüe 滇南礦廠圖略 was printed in 1844 and commissioned by Wu Qijun 吳其濬 (1789-1847) when he served as provincial treasurer and governor-general between late 1843 and May 1845. Alongside Wu, Xu Jinsheng 徐金生 (?-ca. 1840) is credited as editor-compilor and illustrator (輯繪). His last tenure was Dongchuan, which is dated from 1837 to 1840 or shortly before (Yang and Kim 2018, 15-16). Because the two men could not have met, I believe that Wu Qijun assembled existing materials, adding existing materials to Xu Jinsheng’s handbook. Further, because the illustrations and the annotate glossary of terms show consistency as a specific introduction to key matters and terms, while the other parts of the handbook are mainly regulations and excerpts from an older, lost handbook on copper and from Tiangong kaiwu, I believe that the first two book sections are the content provided by Xu Jinsheng. Xu, in turn, may have used records held in the local governments in which he served, presumably with a preponderance of materials held at Dongchuan, as this prefecture was a leading mining area.

Huang Mengju 黄夢菊 (dates unknown) copied documents that he composed during his official career in Yunnan in a private work entitled Diannan shishi 滇南事實. An excerpted report that Huang submitted to the provincial government during his term in office as Huize 會澤 magistrate from 1843 to 1846 presents specific conditions at the Kuangshan 礦山 mines.

Drawing on these complementary works, this research note attempts an identification of the ores exploited that in part specifically record the Kuangshan mines in northeastern Yunnan and presumably represent knowledge on ores passed on to mining administrators in Yunnan and adjoining southwestern regions.

Dianan kuangchan tulue begins with a definition of technical terms relevant for the administration of mines. This section was probably copied from existing handbooks or guides, possibly with updates. Records on silver ores read:

銀以胚子稱，礦一觔得銀一分為一分胚子，即可入罩曰炸礦，先入爐並成鐮條而後下罩曰大火礦 […]

曰銀礦凡數十種，墨碌爲上，鹽沙次之，有一兩至七八兩胚子；荍麫黃、火藥酥又次之，之些炸礦也。

曰鐮礦即黑鉛也。曰明礦，有大花、細花、劈柴之別，不過數分胚子。

曰銅蓋銀：黑礦起鹽沙，或發亮皆有銀，先入大爐煎出似鐵非鐵，次入推爐即分金爐，推去鐮臊，末入小爐揭成銅，其鐮下罩出銀

曰銀蓋銅：礦色帶綠或夾馬牙者皆有銅，罩中撥出渣臊入大爐煎出鐮，水所剩之渣臊上窯鍛煉幾次，入銅爐成銅。(Wu Qijun 1884, juan 1, p. 6-7)

Silver is referred to in peizi, one centi-peizi being 0.01 liang silver obtained from 1 jin ore. Ore that can be directly loaded into the cupellation furnace is called frying ore; that which has to be first loaded into a smelting furnace and made into silverized lead rods that are then placed into the cupellation furnace is called great fire ore.

There are several tens of different silver ores. The best is the green-black, followed by salt granules. These contain between 1 liang and up to 7-8 liang peizi. Next are buckwheat flour-yellow and gunpowder crisps; all these are frying ores.

Silverized lead ores are lead. They are called bright ores and there are large flower, fine flower and chopped brushwood. These contain only a few centi-peizi.

Copper-silver ores: black ore with salt granules or glittering ore contains silver. It is first loaded in large furnaces and smelted into something resembling iron, then it is loaded into push-furnaces, where the metals are separated, and the lead pushed into a lumpy slag. Finally it is loaded into small furnaces which expose the copper, while the silverized lead is loaded into cupellation furnaces to obtain the silver.

Silver-copper ores: All ore that is greenish in colour or with interspersed horse teeth contains copper. In cupellation furnaces the slags are tapped in loaded into large furnaces to be smelted into silverized lead. The slags remaining in the bath are loaded into roasting hearths and roasted several times, and then loaded into copper smelting furnaces to obtain the copper. (My preliminary translation)

Huang Mengju details the situation at Kuangshan in a report entitled “Itemized report mining matters” (禀厰情條款):

而勢始悠久，硔生山腹，其寶氣熏烝，透出于石土之外者，谓之引苗，由引苗而开采[石+曹]*硐，谓之破草皮，破草皮後必有攔門鋪山大石，石内仍有紋理一綫，或紅或黄，深入山内者，谓之閂。由閂尋硔，如得有寬厚數寸，或一二尺，而高深不可測量者，名曰成刷。四無邊岸極多而大者名曰成塘。又有箇子硔者，小如栗枣，大如瓜瓞*，每箇自三五觔，至數十觔，或圓或長，大小數十箇叢生于一處者，名曰鷄窝硔。

硔質甚多，五色畢具，各有好歹，縂以體重，而有錫腊者为佳。錫腊者硔之精华，其色精瑩而有寳光也。黄为金箔硔，又為荍麵硔，綠带黑如烏金，為墨綠硔。黑為火藥酥硔，红为硃砂硔，白為石灰脚硔，皆硔之最佳者，每觔可出銀三五錢至二三兩不等。然不能多得，得亦不过寬三五寸為止，穿夾於鐮哄之中。

此外所常有者，或刷或塘，曰大火硔，亦有大花、明硔、柳條、花發、竹黄、緞子邊等名，皆鐮哄而内有銀银味也。大火硔入爐用炭煎煉，每三百斤先出黑鐮，多者三百斤，少者百余斤，再于鐮内取銀[貝+呈]**分好者，每硔百斤可取銀四五兩，輕者二三兩，有不及一兩者，不敷油米炭工。(Huang Mengju 1849, juan 1, 58)

Over very long processes, ore forms inside the mountain, and the precious vapours evaporate and eventually penetrate to the rocks and ground on the surface. This is called leading sprout, and when excavating a ming working begins following a leading sprout, this is called breaking the grass skin. Once the grass skin is opened there will by a gate-like formation into the massive rock, and inside the rock the thread will continue, either red or yellow, penetrating deep into the mountain; this is called bolt. Following the bolt the ore can be found, when it is found, it may be several cun wide and thick, or 1-2 chi, and when it is so high and deep beyond measuring, it is called a full swipe. When it is so great that the border are invisible, it is called a full pond. There are also lumps of ore, some as small as chestnuts or dates, other as large as pumpkins, a single lump may weigh 3-5 jin or even several 10 jin, they may be round or oblong, and when many have formed together, this is called chicken nest ore.

There are many grades of ore and they come in all colours, each with specific aspects and generally measurable by weight. The best is tin wax. Tin wax is the most refined ore, lustrous in colour and with a precious shine. Yellow is golden leaf ore, also buckwheat flour ore, greenish with back as black gold is black-green ore; black is gunpowder fries ore, red is cinnabar granule ore, white is line-feet ore. All these are the best ores, with silver yields between 0.3-05 up to 2-3 liang per jin. But these are rare finds, and when found are at most 2-4 cun thick, packed into silverized lead ores.

Apart from these the common ores, which form swipes and ponds, are called great fire ores, and subdivided into large flowers, bright ores, willow branches, emerging flowers, yellow bamboo, satin rim and so forth. All these are silverized lead ores. Great fire ores are first loaded into furnaces with charcoal and smelted for black lead, for 100 jin some 300 jin are required, at best only over 100 jin; and from this silverized lead the silver is again separated. A good yield is 4-5 liang from 100 jin, low yields are about 2-3 liang, and below 1 liang the yield falls below costs for oil, rice, charcoal and labour. (My preliminary translation, paragraphs added)

Notes: * Characters that are not in readily represented are shown by components in square brackets, e.g. [石+曹], here adit or working
** the probable reading of the character [貝+呈] is 成

 

Both texts discern two groups of ores, namely “frying ores” (zha kuang 炸礦), could be directly cupellated,  and “great fire ores” (dahuo kuang 大火礦) or “bright ores” (ming kuang 明礦), which were smelted for rich lead first. In modern terms, “frying ores” are evidently rich silver ores, while “great fire” or “bright” ores are silverized galena. In addition to silver ores, Diannan kuangchan tulue records copper-silver and silver-copper ores that required special treatment. Both the ores and the treatments are relatively mysterious.

Silver yields

The first obvious finding is the considerable difference between the yields recorded in Wu Qijun  and Xu Jinsheng and in Huang Mengju. Converted to metrical values, the data are:

Table 1: silver yields
Type of ore	Wu Qijun	Huang Mengju	Zhao Yanwei
Frying ores, highest grade	43.75%-50%	12.5-18.75%	7500-5000 g/t 750-1000 g/t
Frying ores, low grade	6.25%	3.13-1.88%
Great fire ores, highest grade	around 3125 g (assuming 5 peizi)/t	2500-3125 g/t
Great fire ores, low grade		1250-1875 g/t
Lower limit of economically viable exploitation		625 g/t

The discrepancy might reflect that Huang recorded data he obtained for Kuangshan in the early 1840s, while Wu and Xu used data from several mining regional and conceivably also recorded considerably earlier. Kuangshan is a huge and ancient, but almost unrecorded mine. It appears as a tiny silver mine in the written records only in the early 19^th century, while a zinc exploitation is documented from about 1740. Local oral traditions date the beginnings of the mines to the Ming period, and lead slags that have been re-exploited from the 1950s amount to the stunning amount of 1.3 million tons. There is no doubt of longstanding and intensive exploitation, as well as and the parallel working of lead, silver and zinc ores in the later phases of the mines. The fact that modern prospecting found no silver ores shows that historic mining extracted almost all workable veins. As the site was clearly nearing exhaustion by the 1840s, low reported silver contents are to be expected. (For Kuangshan, see Yang and Kim 2021 and https://www.zo.uni-heidelberg.de/sinologie/research/mining-sw/fieldwork/018_kuangshan_huize.pdf). This in turn strongly suggests that the data in Diannan kuangchan tulue represent not the current situation at Kuangshan, but probably record general as well as far earlier conditions in Yunnanese mines.

A memorial by Lin Zexu 林則徐 (1785-1850) contains the only record on the proportion of rich silver ores and silverized galena. In the late 1840s, during a short appointment to Yunnan, Lin petitioned for lifting the ban on trading in metallic lead in the province. There is a strong probability that Lin received his data from Huang Mengju, as much of his other data is similar to Huang Mengju’s extant account. According to Lin only 1% of all extracted ores were rich ores, while 99% were lead ores. Lin further details that the silver content in the lead bullion was at best 3-4 peizi (2,188 to 1,875 g/t) and often merely 1-1.5 peizi (625 to 938 g/t). It appears that the ratio of 99:1 for galena to rich ores and the minimum yield of 625 g/t represent the very lowest limits of exploitable ores. (Lin 2002, 11; Yang and Kim 2018, 32-33).

 

The identification of ores

Drawing on the descriptive names and some notes on the colour and structure of ores, Table 2 provides a tentative identification of the ores recorded in Diannan kuangchan tulue and Diannan shishi. The identification employs Hans Ulrich Vogels related research on copper and silver ores (Vogel 2008) and the descriptive and pictorial materials in Mineralienatlas (https://www.mineralienatlas.de/).

In his analysis, Vogel has identified some designations used for both copper and silver ores. Thus, the best copper ores are recorded as xila 錫腊 (tin wax), with several sub-classifications by colour, while molü 墨綠 (green ink) was another high-grade copper ore (Vogel 2008, 152-161). Huang Mengju records list xila as the richest silver and molü as the second richest ore, while according to Wu Qijun and Xu Jinshen the best silver ore was molu 墨碌. Vogel concludes that rich sulphurous ores were subsumed under the name of xila. It appears that the ores share a greyish colour and a way-like smooth and shine surface. Similarly, nearly-black green and shininess presumably characterized the two rich and important copper ores.

 

Table 1: Ores recorded in Wu Qijun 1844 and Huang Mengju 1849
Name, original	Name, translated	Interpretation of structure and colour; additional information	Identification of leading ore mineral
Rich silver ores
Xila 錫腊	Tin-wax	色精瑩而有寳光 Smooth and shiny	Stephanite
Molu墨碌, molü 墨綠	inkstone or inky green	綠带黑如烏金 Green, almost black, similar to black copper	Argentite
yansha 鹽沙	salt sand	Probably grey-to-black granules (good quality salt of Sichuan and Yunnan was blackish in colour)	Pyrargyrite?
jinbo 金箔	Gold foil	Yellowish, probably forming thin layers	Argentopyrite?
Qiaomianhuang 荍麫黃, qiaomian 荍麵	buckwheat flour yellow	Finely granulated, yellowish grey	Chlorargyrite
huoyaosu 火藥酥	gunpowder crisps	Loose and shiny, probably dark granules	Dykrasite?
Zhusha 硃砂	Cinnabar sand	Reddish granules	Proustite, silverized lead oxide?
Shihuijiao 石灰脚	Lime feet	Whitish	Miargyrite?
Silverized galena
xihua 細花	fine flowers	Fine patterned, relatively rich in Ag*	Galena, differentiated by structure that reflectssilver content
dahua 大花	large flowers	Large patterned, low in Ag
pichai 劈柴	chopped firewood	Block structure, with wood-like grain
Liutiao 柳條	willow branches	Galena with twig-like silver cristallizations?	Galena with andorite or fine argentite branches?
huafa 花發	sprouting flowers	radial pattern	Galena with anglesite?
zhuhuang 竹黄	bamboo yellow	Dull yellow in colour	Galena with argentopyrite?
duanzi bian 緞子邊	Satin seam	Enrichment of galena in contact borders?	cerrusite?
Copper-silver ores
Heikuang qi yansha, huo faliang  黑礦起鹽沙或發亮	black ore with rising salt granules or bright	Perhaps “black copper ore”** with grey granules or shiny inlays	Copper ore compounds containing tenorite and argento-tennantite?
Silver-copper ores
Kuangse dai lü, huo jia maya zhe 礦色带綠，或夾馬牙者	Ore with a greenish hue or interspersed with horse teeth	Greenish, or with large yellowish inclusions	Freibergite or argento-tennantite?

Note:

* Émile Rocher records xiaohua 小花 as the rich silverized galena exploited at Gejiu, explaining that this ore was recognized by its fine facet structures (“à petites facettes”) (Rocher 1879, vol. 2, 239). The description permits aligning this type of ore with xihua. By extrapolation, I assume that xihua was the galena highest in silver content, while dahua was lower and pichai probably still lower.

** heikuang 黑礦 might refer to heitongkuang 黑銅礦, a rich copper ore.

 

 

References:

Huang Mengju 黄梦菊. 1849. Diannan shishi 滇南事實 (Factual titbits from Yunnan). Orig imprint by Yudetang 裕德堂.

Kim, Nanny and Yang Yuda. "The evolution of reverberatory cupellation furnaces in the southwest of late imperial China." Historical Metallurgy 51.2 (2019): 71–86.

Lin Zexu 林則徐. 2002. “Chakan kuangchang qingxing shixing kaicai shu” 查勘礦廠情形試行開采疏 (Investigation of the Situation in the Mines and Suggestions for Trial Exploitations), vol. 1, in Zheng Zhenduo 郑振铎 (ed.), Wanqing wenxuan 晚清文选 (Selected Late Qing Writings), Beijing : Zhongguo shehui kexue chubanshe.

Lu Rong 陸容 (ed.) (1985). Shuyuan zaji 菽園雜記 (Miscellaneous Notes by Lu Rong). Orig. fifteenth century, reprint Beijing, Zhonghua shuju.

Rocher, Émile. 1879. La province chinoise du Yün-nan. 2 vols. Paris: Leroux.

Vogel, Hans Ulrich, 2008. “Copper smelting and fuel consumption in Yunnan, eighteenth to nineteenth centuries.” In Thomas Hirzel and Nanny Kim, eds. Metals, Monies, and Markets in Early Modern Societies: East Asian and Global Perspectives, 119-170. Berlin: LIT.

Wu Qijun 吴其浚. 1844. Diannan kuangchan tulue 滇南矿厂图略. Orig. 1844. Repr. In Xuxiu siku quanshu 续修四库全书, vol. 880. Shanghai: Shanghai guji chubanshe, 2002.

Yang Yuda and Nanny Kim. 2018. “Texts and technologies on Chinese silver metallurgy, twelfth to nineteenth, centuries,” Journal East Asian History of Technology and Medicine 49: 9-82.

Yang Yuda, and Nanny Kim. 2021, “Overlooked Silver: A Reassessment of Silver Supply in Late Imperial China,” Harvard Journal of Asian Studies (forthcoming).

Zhao Yanwei 赵彦卫. 1998. Yunlu manchao 云麓漫钞 (Zhao Yanwei’s random drafts). Orig. 12th century. Reprint in Xin shiji wanyou wenku: Chuantong wenhua shuxi 新世纪万有文库 传统文化书系 (New century library of everything: Traditional culture series). Shenyang: Liaoning jiaoyu chubanshe.