On Minerals

Wood turning into stones. Corals. Similarly, wood that has died in certain waters and seas turns into stone while retaining the shape of the wood. Sometimes, plants growing in those waters and seas are so close to the nature of stones that, after being dried for a short time in the air, they take on the form of stones. The proof of this is the stone called Coral, which is undoubtedly generated from wood and plants.

A miracle For in our own time, a large branch of a tree was found in the Danish Sea near the city of Lübeck, in which there was a bird's nest and small birds in the nest, and they had all turned into stone. The author is describing an early account of petrification, likely caused by mineral-rich waters. Lübeck was a major trading port in the Hanseatic League. The tree had been torn out by the waves at a time when there was a nest and birds in it, and fell into the water; afterward, through the power of the place in which it lay, they were all transformed into stone. There is also a spring in Gothia Gothia refers to the land of the Goths in modern-day Sweden. of which it is most truly reported
The spring of Gothia that it turns everything submerged in it into stone—so much so that the Emperor Frederick Likely Emperor Frederick II (1194–1250), known for his scientific curiosity and experiments. sent a sealed glove to it to test the truth of this. When half of the leather and half of the seal had been submerged in the spring for several days, half of the leather and half of the seal were turned into stone, while the other half of the leather remained as it was. It is also truthfully reported by reliable witnesses that the drops splashed onto the bank of the spring by the force of its fall are turned into stones the size of the drops; yet the water that flows in this way is not turned into stone, but flows continuously. We also see with our own eyes that crystals are generated in the highest mountains where there is perpetual snow; this could not happen except through the mineral power mineral power (virtus mineralis): a "formative force" in medieval science believed to direct the growth of minerals, much like a soul directs a living body present in those places. From all of this, it can be seen that nothing certain can be said about a single location for the generation of stones, since they are found not in only one element but in many, and not in only one climate but in all of them. And what seems even more marvelous is that they are generated in the bodies of living creatures and in the clouds—all of which are places where it seems very difficult to trace them back to one common matter. Yet this is necessary, for we do not doubt that the generation of a mixed body belongs to a single genus. For it is necessary that for all things generated, there is some place of their generation, outside of which they decay and are destroyed.

Chapter Eight, in which the reason is given why certain places generate stones and others do not.

The generative power of the stars Wishing, therefore, to investigate the power in all these places, let us recall what has been determined in the preceding books of natural science: namely, that the stars, by their size, light, position, and motion, move and order the world according to every matter and place of things that can be generated or destroyed. This generative power, determined by the stars, is infused into the place of generation for each thing, in the way determined by the natures of those places. For this power is what produces and generates every element and every composite thing. This power in these locations is

Triple power aggregated from three powers: one of which is the power of the Mover of the Sphere In Aristotelian cosmology, the "Mover" is an Intelligence or spiritual force that keeps the celestial spheres in motion..
First The second is the power of the moving sphere itself, with all its parts and the arrangements of parts that result from the way they face each other differently due to the
Second various speeds and slowness of the Mover. The third is the
Third elemental power, which is hot, cold, moist, and dry, or a mixture of these. The first of these powers is like a directing form, shaping everything that is generated, just as the power of art relates to the material of the object being made. The second is
Aristotle like the operation of the hand. And the third is like the operation of the tool, which the hand moves and directs toward the end intended by the craftsman. Therefore, Aristotle says that "every work of nature is a work of intelligence." For the place receives these powers just as the womb matrix: used here in its Latin sense of "womb" or "breeding ground" receives the formative power of the embryo. This power, determined for the generation of stones in earthy or watery matter, is where all the places in which stones are generated agree. For just as in animals generated from decay referring to "spontaneous generation," the now-debunked theory that some life forms arise from rotting matter a life-giving power is infused from the stars, so it also happens in the matter of stones that a formative power of stones is infused in the said manner. Therefore, in whatever place oily earth is mixed with vapor reflected back into itself, or in which the powers of the earth take hold of the nature of water and pull it toward dryness and incline it strongly, there is certainly a place for the generation of stones. Because of this, the solid surfaces of the earth, from which such vapor cannot escape, generate many stones. However, in soft, muddy earth, which stains water rather than taking hold of it, stones cannot be generated in their proper properties. And this is the reason why many stones are generated on the banks of eternal rivers: for such banks are very solid, trapping the rising vapors within themselves.
The cause of the stoniness of banks Those banks are vaporous because the heat excited by the reflection of light upon the waters is repelled by the coldness of the water toward the shore; trapped in the parts of the earth, it "cooks" original: "decoquit"; a term from alchemy and early chemistry meaning to refine or harden through heat and hardens the earth mixed with water. For the same reason, the bottom of such rivers is made stony, because the heat on the shores penetrates into the earth under the water; and since the water fills the pores everywhere through which it could evaporate, it simultaneously mixes and cooks the mixture into stones. This is why such places are generative of stones. There is also the flow of certain waters through very strong mineral powers, and when they flow through such materials, they soak up the minerals themselves; and therefore both the water and the things submerged in them turn into stones, more quickly or more slowly according to how the formative and making power of stones is strengthened or weakened. The reason why water split off near a bank and poured out from a spring turns into stone more quickly than the water flowing from a spring, river, or sea, is that this power overcomes a small and divided thing more quickly than a large and undivided thing—as is true of every power that transforms something; for every such power transforms a small thing more quickly than a large one. If the same water poured out in another place does not turn into stone, it is because it is outside the mineral place.