麦饭石，文具姜石条下。
\r自然铜\ph62.bmp\r，生邕州山岩中出铜处，今信州、火山军皆有之，于铜坑中及石
间采之。方圆不定，
其色青黄如铜，不从矿炼，故号自然铜。今信州出一种如乱铜丝状，云在铜矿中，山气熏蒸
，自然流出，亦若生银如老翁须之类，入药最好。火山军者，颗块如铜，而坚重如石，医
家谓之 石，用之力薄。采无时，今南方医者说∶自然铜有两、三体∶一体大如麻黍，或多
方解，累累相缀，至如斗大者，色煌煌明烂如黄金、 石，最上；一体成块，大小不定，亦
光
明而赤；一体如姜、铁矢之类。又有如不冶而成者，形大小不定，皆出铜坑中，击之易碎，
有黄赤，有青黑者，炼之乃成铜也。据如此说，虽分析颇精，而未见似乱丝者耳。又云∶今
市人多以 石为自然铜，烧之皆成青焰，如硫黄者是也。此亦有二、三种∶一种有壳如禹
余粮，击破其中光明如鉴，色黄类 石也；一种青黄而有墙壁，或纹如束针；一种碎理如团
砂者，皆光明如铜，色多青白而赤少者，烧之皆成烟焰，顷刻都尽。今药家多误以此为自然
铜，市中所货往往是此。自然铜用多须 ，此乃畏火，不必形色，只此可辨也。
\r石燕\ph63.bmp\r，山零陵郡，今永州祁阳县江旁沙滩上有之，形似蚶而小，其实石
也。或云∶生山洞
中，因雷雨则飞出，堕于沙上而化为石，未审的否？今人以催生令产妇两手各握一枚，须臾
子则下。采无时。
麦饭石，在“姜石”条目下已有记载。
自然铜，产于邕州山岩中出铜的地方，如今信州、火山军也有出产，在铜矿坑中和石头间采集。形状方圆不定，颜色青黄像铜，不经过矿石冶炼，所以叫自然铜。如今信州出产一种像乱铜丝形状的，据说在铜矿中，受山气熏蒸，自然流出，也像生银像老翁须之类，入药效果最好。火山军出产的，颗粒块状像铜，但坚硬沉重像石头，医家称为“石”，药效力量薄弱。采集没有固定时间，如今南方医生说：自然铜有两三种：一种大如麻籽黍米，或有多方解，累累相连缀，大到斗大的，颜色辉煌明亮像黄金、琉璃，是最上等；一种成块状，大小不定，也光明而呈红色；一种像姜、铁箭头之类。又有像未经冶炼而成形的，形状大小不定，都出自铜矿坑中，敲击容易碎裂，有黄赤色，有青黑色的，冶炼之后才成为铜。根据这样的说法，虽然分析颇为精细，但没有见到像乱丝那样的。又说：如今市场上很多人用“石”冒充自然铜，烧它都会产生青焰，就像硫黄那样。这也有两三种：一种有壳像禹余粮，敲破其中光明如镜子，颜色黄类似琉璃；一种青黄色且有纹理，有的纹路像束针；一种碎理像团砂的，都光明像铜，颜色多青白而赤少，烧之都成烟焰，顷刻全部烧尽。如今药商多误将此当作自然铜，市场上售卖的往往是这些。自然铜使用大多需要煅制，此物畏火，不必看颜色和形状，只凭这一点就可以辨别。
石燕，产于零陵郡，如今永州祁阳县江旁沙滩上有，形状像蚶但较小，其实是石头。有人说：生长在山洞中，遇到雷雨就飞出，落在沙上化为石头，不知是否确切？如今人用来催生，让产妇两手各握一枚，一会儿孩子就降生。采集没有固定时间。
Mifan Shi (Mifan Stone), recorded under the entry for Jiang Shi (Ginger Stone).
Ziran Tong (Natural Copper) is produced in the mountain rocks of Yongzhou where copper emerges. It is now also found in Xinzhou and Huoshan Jun, collected from within copper pits and among stones. Its shape and size are irregular; its color is greenish-yellow like copper. Since it does not require smelting from ore, it is called "Natural Copper." Currently, a variety resembling tangled copper wires is produced in Xinzhou; it is said to naturally flow out within copper mines due to the steaming effect of mountain air, similar to how native silver resembles an old man's beard. This variety is considered best for medicinal use. The specimens from Huoshan Jun are lumpy and resemble copper but are hard and heavy like stone; physicians refer to them as "Shi" (Stone), noting their therapeutic efficacy is weak. They can be collected at any time. Physicians in the south currently describe two or three types of Ziran Tong: one type is as large as hemp or millet seeds, often with multiple facets, linked together, up to the size of a peck measure, with a brilliant, bright color like gold or glaze; this is the highest grade. Another type forms into blocks of varying sizes, also bright and reddish. A third type resembles ginger or iron arrowheads. There are also forms that appear unsmelted, with indeterminate shapes, all originating from copper pits; they shatter easily upon impact, appearing yellow-red or blue-black, and only become true copper after smelting. Although such descriptions offer detailed analysis, the wire-like variety has not been observed. Furthermore, it is reported that many vendors currently pass off "Shi" (Stone) as Natural Copper; when burned, these produce a blue flame, similar to sulfur. These impostors come in two or three varieties: one has a shell like Yuyuliang (Halloysitum Rubrum); when broken, the interior is bright like a mirror, yellowish in color like glaze. Another is greenish-yellow with distinct layers or patterns resembling bundled needles. A third has a fragmented texture like clumped sand. All appear bright like copper, predominantly white-blue with little red, and burn completely to smoke and flame in an instant. Many apothecaries mistakenly identify these as Natural Copper, and market goods are often of this nature. Authentic Natural Copper usually requires calcination; however, since the material fears fire, one can distinguish it by this property alone, without relying on color or shape.
Shiyan (Stone Swallow) is found in Lingling Commandery. Currently, it exists on the sandy beaches beside rivers in Qiyang County, Yongzhou. Its shape resembles a clam but is smaller; it is actually stone. Some claim it grows in mountain caves and flies out during thunderstorms, falling onto the sand to transform into stone, though the accuracy of this is uncertain. Currently, people use it to facilitate childbirth, having the laboring woman hold one in each hand, after which the child is delivered shortly. It can be collected at any time.