nevertheless they can burn the skin so badly that it appears to have been cauterized. Some natural atramentum sutorium has this same property. Sory is
identified by its black and shiny surface when broken, by its many
openings, it sub-unctuous quality, its strong harsh odor of lightning
and its power to destroy odors of the gullet, especially the mineral
from Egypt which Dioscorides regards as the best.20 The best chalcitis is that which, when fresh, has the color of copper, occurs in long shining fibers and crushes easily. Misy can
be identified by its hardness, its golden color, its luster which
resembles polished gold and its sparkle which resembles the stars. The
best melanteria has the color of sulphur but blackens rapidly when placed in water.21
Since I have discussed natural atramentum sutorium and
the related minerals that form from cupriferous pyrite it follows that
I mention the congealed acid juice which usually produces cadmia. This
mineral is found in the underground workings of the St. Otto mine at
Annaberg. It is white, hard, and so acrid that it can eat away walls,
grills and even destroy all living matter. The very tenuous material
that exudes from mountain rocks and the dense material that hangs from
the back of underground workings and caves, from which they make halinitrum, is commonly acrid but it does not produce cadmia.
I shall now describe chrysocolla, caeruleum, armenium and aerugo since these are commonly found in mineral veins, especially copper veins. The Greeks first gave the name chrysocolla to
the artificial compound used in soldering gold and subsequently natural
minerals as well as other artificial compounds were given the same
name because of a certain similarity in color. There are two kinds of chrysocolla, native and artificial. The native mineral occurs in veins and fractures and is found either pure, similar
20 Black
water-soluble sulphates are rare. There are only two to which he might
have reference, voltaite and glockerite. Both minerals occur at Goslar
and at other mines in the Harz district. Glockerite has been reported
from near Zuckmantel.
These
description indicate that Agricola confused, at times, other minerals
viz. hydrous oxides, silicates, etc., with sulphates. However his
statement that "all five minerals are soluble in water" indicates that
he must have observed some black soluble sulphate mineral.
Veins
containing porous marcasite and pyrite, especially when they are
alteration products of pyrrhotite, oxidize first to a mixture of free
sulphuric acid, melanterite and finely divided iron sulphide which
gives the mixture an intense black color. It is possible that Agricola
may refer to this mixture when speaking of black melanteria and in part black sory.
21 Agricola has mentioned these minerals in other works. The following extract is of particular interest. See Footnote 15.
De Natura Eorum Quae Effluunt ex Terra, Book I, p. 108, "Atramentum sutorium is rarely white, commonly green or blue. Among the related minerals misy is golden yellow; chalcitis is copper-colored; sory and melanteria almost always black although the latter is usually gray when dried. 'Book II, p. 121,' Atramentum sutorium, like other acid substances, dyes black and, like other penetrating substances, will produce sneezing."