The scientific value of Yunlin Stone Spectrum is highlighted in the description of minerals and rocks. For example, the description of the optical properties of Bodhisattva stone is "its color is bright and clean", "it reflects sunlight and emits five-color light" and "it is as big as jujube chestnut, but its luster is weak, as small as cherry beads, and the five colors are gratifying". Bodhisattva stone is a crystal, which is a transparent and timely crystal. When sunlight passes through the crystal, it will scatter and form a "five-color round light". Wandu describes many colors of stones, including white, cyan, gray, black, purple, blue, brown, yellow and green. In addition, there are also differences in color depth, such as dark green, light green, turquoise, purplish, blackish, bluish and grayish black. He also saw that the stone would change color after weathering, and the newly unearthed Lingbi stone was pale. "If exposed for a long time, the color will turn white." Wandu pays great attention to the sound of stones. He often hits the stone with something, and the result is loud, audible, slightly audible, clear and silent. According to the author's statistics, most limestone recorded in known books has sound, some of which are clear. Soft shale has a low or silent sound, while hard shale has a high sound. Pyrophyllite, talc, crystal and the like basically have no sound like limestone.
Wandu's editorial description of stone hardness is quite detailed. He used eight grades to distinguish the hardness of stones: very soft, slightly soft, slightly hard, not too hard, hard, quite hard, very hard and difficult to chisel. It is undoubtedly scientific to be so fine more than 800 years ago. Wandu also noticed the thickness of the stone surface, which is divided into 1 1 grades: rough and boring, dry, quite rough, slightly rough, slightly rough, very smooth, clear, moist, firm, slightly moist and fine.
For all kinds of grotesque stones used as rockeries, Wandu explained that their causes were "wind and wave impulse" or "feng shui impulse fusion". He also recorded the technology that people used feng shui impulse to process Taihu stone at that time: firstly, the Taihu stone was preliminarily processed and carved into the required shape, and then "the stone was naturally like life after being soaked in water for a long time and washed by feng shui".
Wandu has a high understanding of fossils. He not only recorded fish fossils and marine brachiopod shell fossils-Shiyan, but also clarified the origin of fish fossils with experiments and clarified the misunderstanding that Shiyan could fly. These viewpoints play an important role in the ancient geological history of China.
In addition to the above contents, Yunlin Stone Spectrum also introduces the uses of various rocks, such as making rockeries, making research screens, making inkstones and other utensils and toys. The method of workers processing stone at that time was also introduced.
Yunlin Stone Spectrum is the most abundant stone spectrum in Song Dynasty, and Wandu is an accomplished mineral petrologist in Song Dynasty.