Quantcast
  Due to a new server, slow response may occur for which we apologize Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/agricola_textbook_of_mineralogy/page_065 - 2
 

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
BOOK III
53
is found abundantly and in many places in Spain according to Pliny; in small amounts in Germany; abundantly at Neusohl, Dacia; in Macedonia, Cyprus, Armenia and on Damonesus, a Carthaginian island. That from Armenia has such a deep color that it resembles prase.24 Dioscorides gives preference to this material and second place to that from Macedonia. However the quality of the mineral is more properly judged from its color and nature which are related to the place of origin. Although the native mineral is always green there is a wide variation in the tone. It may be a deep green and while it adheres to the metallic vein material it may approach the color of the emerald and this was considered the best for a long time. The mineral with the least value is pale green and that with intermediate tones has an intermediate value. The artificial material which is tinted yellow is the color of the carob tree and for that reason is called όροβίτηs by the Greeks. Since so much work is put into the preparing, grinding and coloring this chrysocolla is sold at a higher price than the rest because of the higher costs. Pliny has given us the relative values of three different grades, aspera similar to hard sand, seven denarii a pound, media which sinks rapidly in water or can be crumbled in the hand, five denarii, and attrita that can be crumbled in the hand and is colored with saffron, thirteen denarii. Today aspera and media are worth about one and one-half denarii a pound. We do not have the attrita.
Painters use chrysocolla of all kinds. Metal workers use only that which cements gold to gold and silver to silver.25 Medical men use both the arti­ficial and natural minerals and the latter, for that reason, is called άκέσis by the Greeks. Both are drying and corrosive but even when they eat away the flesh they do not cause excessive pain. For this reason the mineral is used in the treating of ulcers which will not heal. The artificial mineral is more tenuous, dries more and causes less pain than the natural mineral. When burned it becomes more tenuous as do all minerals as Galen has correctly stated. A small quantity causes vomiting and a large quantity is fatal. Pliny writes that Nero spread chrysocolla on the great race course of the arena when he was going to compete in a chariot race so that the course would look like a piece of cloth. Chrysocolla is so closely related to caeruleum, which the Greeks call kvclvos, that these two congealed juices are frequently formed at the same time and may be found adhering to the same piece of ore. When they form together one is seen to surround and enclose the other. Sometimes there is more caerule­um, as Theophrastus has observed, sometimes more chrysocolla and some­times they occur in equal quantities as I have observed.26
21 This is evidently taken from Dioscorides and probably refers to mineral from the Katara copper mine.
25 Borax.
28 According to these descriptions the name chrysocolla was given to various natural blue and green minerals which, by definition, contained copper and were not soluble in water. The two principal minerals were the copper silicate, chrysocolla
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
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page