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Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo

Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Page of 251 Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Text size:minus plus Restore normal size   Mail page  Print this page
52                                      DE NATURA FOSSILIUΜ
to sand, or adhering to vein material. When scraped from the vein ma­terial the latter mineral resembles the sand, although sometimes the coating is so thin that little or none can be removed. When water removes the mineral from veins it settles out in a fine powder. A green mine water of this kind flows from an ancient underground working at Neusohl in the Carpathian Mountains. A volume sufficient to fill thirty castles is im­pounded and the mineral permitted to settle out. This is collected each year and sold in lots. The production from Neusohl is obtained without human effort and Pliny describes a similar case where the mineral is obtained artificially. The light summer rains that fall in June were directed into a vein and then collected and allo\ved to evaporate in the sun during June and July.22
There are two species of artificial chrysocolla, one made from the hard native mineral then colored with saffron and hence named for this herb. This is the best and is more valuable than the native mineral. Pliny de­scribes how it is made. The native mineral is dried on wool or linen and then crushed in a mortar and sieved. The coarse material is crushed again and this process continued until it all passes through the sieve. It is then ground in a mill. The fine material is placed in a shallow vessel and macer­ated with vinegar until it becomes soft. It is again ground in a mortar and then washed in shells and dried. After drying it is moistened with a solu­tion of alum and colored with saffron. It is important that it take the color readily and uniformly. If it will not take the color at once scythanum23 and turbystum are added. These substances will cause the color to be ab­sorbed. Painters call a similar color orobitin. There are two varieties of this made in Cyprus, one a clay that is preserved in unguents, the other a liquid, according to Pliny.
The chyrsocolla used by craftsmen and classified by Dioscorides as a variety of aerugo is described as a metallic mixture produced from Cyprian aerugo, the urine of young boys and nitrum. Galen, writing later than Dios­corides, states that it is made only from aerugo and urine. Since there is a lack of Cyprian copper this variety of chrysocolla cannot be made and the other variety, which I have already mentioned, has replaced it. This is adulterated with powdered chalk that has first been colored with aerugo and in this way a large amount is obtained from one pound of pure mineral. This practice, although deceitful, actually is not contrary to nature which also colors chalk green. At one time chrysocolla was made from a yellow herb and finely ground caeruleum. Neither of these adulterated or falsified products is recommended since each is worthless.
But to return to the natural mineral which is found in copper mines since it forms only from copper. When it occurs in gold, silver or lead mines it is certain that copper also occurs in the same veins. This mineral
22 This is probably a reference to some green sulphate rather than to either chrysocolla or malachite.
23  Also written scytanum and scytatum by different authors.
Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo Page of 251 Book III about halite and nitrium, alum and acrid juices and related minerals, sulphur, bitumen, realgar, and orpiment; the fourth, chrysocolla, aerugo, caeruleum, ferrugo
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