Gems 宝石
Gems or precious stones (baoshi 宝石) is an evidently highly unscientific category to subsume and mineral that people in some period regarded as precious and were willing to pay elevated prices for. The reason to include this category is that the exploitation in part overlaps with mining for metals, as some gems are metal minerals. Moreover, intense exploitation could lead to mining. Gems, like metals, are stable, valuable, and not affected by long storage. They are hence an ideal trade good where great distances had to be overcome across difficult mountain terrain. Even more than metals, stones gained with rarity. A pretty stone might be had for picking it up where such stones were abundant. It became a precious object by being polished, but mainly by fashion and cultural value, often in distant regions where pretty stones were not to be found.
The Far Southwest was known to produce gems and trade in precious stones presumably existed since prehistoric times.
Gems that became economically important were Burmese jades and rubies. These stones were in great demand, especially in China. Exploitation was mostly in northern Myanmar, with some ruby mines in the southern uplands, and employed pit and shaft mining. The trade in precious stone played an important role in trade routes, specifically favouring the route from Dali 大理 via Baoshan 保山 and Tengchong 腾冲 to Bhamo on the Irrawaddy in northern Myanmar. A link between this route and the mobility of Chinese miners appears probable. During the Ming and Qing periods, Chinese miners and metallurgists from Hunan 湖南, Jiangxi 江西, Shaanxi 陕西 and other provinces played a decisive role in the development of large-scale silver mining in the borderlands. A number of these mines (Mingguang 明光, Munai 慕乃, Maolong 茂隆, Bawdwin, as well as the mysterious Ming mine Xinglong) were on or near major trade routes (Kim 2019).
Gems were exploited at many other sites across the region. Some recorded ones were lü 绿, probably emerald; bidianzi 碧甸子, probably turquoise; fan 矾, white or translucent crystals; pi 砒, arsenic oxide; and qingshi 青石, copper carbonate. Some stones were not necessarily precious, but still valued. Thus, an 18th century record mentions that sets of black and white weiqi 圍棋 stones from Yongchang 永昌 (Baoshan) were a standard gift in the official class (Tongyun shengguan jue 銅運升官訣, anonymous manuscript, ca 1811).
Gems evidently are beyond the focus of this project. We consider them only inasmuch as co-exploitation of metals and gems is a possibility at some deposits, and as mineral knowledge and exploitation skills were linked.
