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Book I Minerals color, taste, odor , physical properties of gemstones and minerals such as emeralds, diamonds, rubies, sapphires

Book I Minerals color, taste, odor , physical properties of gemstones and minerals such as emeralds, diamonds, rubies, sapphires Page of 251 Book I Minerals color, taste, odor , physical properties of gemstones and minerals such as emeralds, diamonds, rubies, sapphires Text size:minus plus Restore normal size   Mail page  Print this page
12
DΕ NATURA FOSSILIUM
stones, and earths do not. Some that burn are entirely consumed such at sulphur and bitumen while others are only partly consumed, for example spinos. All that burn, since they are unctuous, produce soot, and, in fact, soot is obtained from the copious smoke and vapor given off by these unctuous substances when they are burned.
Concerning the minerals which do not burn, some can be set on fire: for example, all metals except gold can be entirely consumed. Some can be melted, such as gems and the stones similar to gems; and some can be reduced to a powder, for example, earths and stones moistened with water. Many gems do not melt in ordinary fires and some stones are hard­ened, for example, those found on Siphanto and Como, Italy. Fire can be produced from pyrite, lapis molaris, flint, quartz, and other hard sub­stances. Some rocks are hardened by exposure to the sun and air while others are softened and when moistened by rain, disintegrate.
Vinegar attacks some minerals such as the gem astroites, which our people have named for victory (sigstein) and not uncommonly trochites. When some minerals are placed in water they swell like a bubble such as certain earths. Some float on water if whole and sink when broken into small pieces, for example, pumice, lapis thyreus, and bricks made from pumaceous earth. Galactites, goethite, and hematite yield a juice when pul­verized. That of galactites is white; of goethite, commonly saffron-yellow; and of hematite, blood-red. The juice from galactites is sweet while that from goethite and hematite is astringent. Some minerals tint metals, for example, cadmia, iron, copper. If cadmia (zinc carbonate and silicate) is added to copper it forms brass and if iron is added to copper it forms white copper. Certain genera of earths and stones impart their color to anything. White chalk makes white lines, green chalk called theodotion, green lines, black chalk, black lines. Silver, although white, makes a black line on wood. Eretria earth rubbed on copper gives it a violet color. Flint and sandstone sharpen iron. Lodestone attracts iron while theamedes repels it. Amber and jet will attract chaff, hair, and straws, while some even acts as lodestone and will pick up light objects. When flint is used to sharpen iron it sacri­fices something for, during the process of sharpening, it loses some of its bulk, something is taken away. Likewise chalk, when used to make marks, sacrifices something and since it is entirely consumed with repeated use, something is taken from it. Other minerals have this same property.
Minerals that are taken in food or drink may be either a remedy or a poison and possess a characteristic power that accomplishes something while they themselves suffer some change. Minerals that act as a remedy heal the body in part through an essence that is characteristic of all such minerals and in part through some efficacious quality of purity. Some min­erals rich in this peculiar essence counteract poisons, some cure disease. Others, endowed by Nature with the power of counteracting poisons cure people ill with the plague. Smaragdus, and Lemnian and Armenian earths have this property. Others counteract a single poison as does lapis-lazuli
Book I Minerals color, taste, odor , physical properties of gemstones and minerals such as emeralds, diamonds, rubies, sapphires Page of 251 Book I Minerals color, taste, odor , physical properties of gemstones and minerals such as emeralds, diamonds, rubies, sapphires
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