Caeruleum may be a natural or artificial mineral. Native caeruleum, like native chrysocolla, is
found as the pure mineral in veins or fractures, as gravel or fine sand
or is scraped from vein material. There are many varieties of the
artificial mineral some of which are more valuable than the natural. I
shall explain how the former are made in Book IX. Three distinct genera
were used by the Greek people, two natural genera from Scythia and
Cyprus and an artificial genus from Egypt. The Romans used these three
as well as a native mineral from Spain and an artificial mineral from
Pozzuoli. The Greeks did not know of the native mineral of the
Carthaginians that was dug from mines on the island of Damonesus. Caeruleum is
found not only in copper mines but also in gold and silver mines. The
caverns of the island of Cyprus formed by the action of sea waves
contain veins which produce this mineral although Dioscorides has not
explained in what fashion. Today the native mineral is obtained from
mines in Germany, Dacia, Noricum and Raetia although in small
quantities since the artificial mineral is more widely used. A
considerable quantity is produced from the highest peak of the Sudetes
mountain which is erroneously called Pine Mountain and from Ligyes near
GoldĀberg. Caeruleum is adulterated in India by dissolving the true mineral
and the basic copper carbonate, malachite. Later, in his Interpretatio, Agricola apparently recognized malachite as a distinct mineral with the Latin name molo-chites. The artificial mineral borax, a hydrous sodium borate, was also included under this name. Agricola uses the Latin name borax for this mineral and recognized the relationship with hydrous sodium carbonates which he called nilrum.
The following quotations are taken from other writings of Agricola. De Ortu & Causis Subterraneorum, Book III, p. 47. "Chrysocolla forms
in veins when a metallic substance is moistened with water and then
dried. Proof of this is offered by copper pitchers or vessels used in
baths. If such a vessel is moistened often and over a long period of
time it will have a green efflorescence when it dries." (The basic
copper chloride atacamite and the basic copper sulphate brochantite
form under these conditions and later may be converted into the basic
copper carbonate malachite.) Bermannus, p. 454.
Naevius. "... Chrysocolla itself
is quite green. Dioscorides says that the finest comes from Armenia,
the next best from Macedonia and after that the Cyprus material but
this mineral is not obtained from any of these places today. Bermannus.
"The Dacian mineral is good and equally good material can be obĀtained
in our mines, especially our copper mines. Naevius. "Pliny regards the
mineral obtained from copper mines as the best. He writes that the
second best chrysocolla comes from silver mines, the third
quality from gold mines and the poorest from lead mines. Bermannus.
"Speaking of the artificial mineral, Pliny and your Galen have given it
the same name while Dioscorides classes it under aerugo. I do
not care to say anything now concerning the mineral used by goldsmiths.
Naevius. "... But the artificial mineral has the same properties as the
native mineral since it breaks up and stops gatherings, checks fleshy
growths and still does not produce much pain. Ancon. "The Arabs were
familiar with both kinds. They write that it will also retard the decay
in teeth and stop toothache."