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Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica

Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Page of 251 Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Text size:minus plus Restore normal size   Mail page  Print this page
BOOK V
99
may be large or small, sometimes striated and moderately hard. Some­times the armatura is the color of iron and even diamond. When it is found in an aluminous earth it has a golden copiapite-like color and when found in other types of earth it has the color of iron or some other material. Iron sulphates and alum can change the iron color to that of brass which is similar to gold. In this same locality a gray stone is found with the same shape but entirely free of armatura. Pliny calls this tephritis. Pliny writes that hephaestites found in Corycus has the properties of a glass in that it will reflect an image even though it is red. The name comes from the fact that it will set fire to dry material when held in the sun just as a concave glass sets fire to sulphurous material, straw and small twigs. Stones of this genus, with a dark red color, are found in the moat on the north side of Hildesheim. They have been found the size of a dish with the red gleam of golden armatura. This material also reflects an image and when held in the rays of the sun will set fire to dry material. Stones are found in this same place ornamented with armatura in such a manner that it appears to be sprinkled with gold.
Myrmecias, a black stone, derives its name from the fact that it has protuberances similar to warts. Pliny classifies it as a gemstone.27 Some stones have markings which resemble the feathers of birds, for example hieracites which Paulus Aegineta classes as a stone and is more correct than Pliny who regards it as a gem.28 This, the latter affirms, shows vari­able shades of black similar to the feathers of a kite. It is found in the Hildesheim district where the road goes from the west moat through the hills on both sides of the river and is similar in appearance and color to the softer feathers on the breast of hawks. Another stone is found in this same place that resembles the feathers from the breast of a partridge, having the same ridges and colors. Hieracites bound to the right thigh is said to stop profuse bleeding from a severed vein. Ammonites is formed from sand in such a manner that it has the appearance of fish roe and inside it some­times has the same form and even the same color and texture.
A certain genus of stone is found in Saxony near Alfeld and Hildesheim the size of a walnut or even larger. They belong to the same genus that I shall describe in Book Seven. Lepidotes (mica) is similar to the scales of fish with variable colors.
I shall describe now certain stones found in the district of Hildesheim. A stone is found in a water course inside a cave that takes its name from dwarfs, with a dark color, tabular form, as harsh as sal ammoniac and having protuberances on the upper surface that resemble the heads of nails. Another stone is found near Hasda which is similar except that it is white and has no protuberances. In the mountainous region where the tem-
27  Pliny, Book 37, Chapter 72, describes this mineral as amber, or a mineral con­taining an ant. He makes no mention of protuberances. The name is derived from the word for ant, myrmeois.
28  Probably arborescent coatings on rocks.
Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Page of 251 Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica
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