Merrifield, Mary P.: The art of fresco painting, as practised by the old Italian and Spanish masters, with a preliminary inquiry into the nature of the colours used in fresco painting: with observations and notes (London: Charles Gilpin, 1846)

IN FRESCO PAINTING.

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sand stone. A similar sand stone, at Gourock near Greenock, in
Scotland, was, a few years ago, dug out for the purpose of extracting
copper.—(Enc. Brit. Art. Mineralogy.)
The resemblance between this species, and the mineral described
by Agricola, is obvious. The indurated species is rare. Azure cop-
per ore is found in veins of primitive and secondary mountains,
chiefly with the green carbonate of copper and red oxide of copper,
in Chili, Bohemia, the Hartz, Saxony, the Uralian mountains, and in
Thuringia, at Chessy in France, &c.
In Cornwall, sparingly in Huel Muttrell and Huel Gorland, Huel
Unity, Huel Virgin and Carbarack. In the Buckingham mine, near
Bridgewater, Somersetshire. At Alderley Edge, in Cheshire, in
sandstone with yellow copper and barytes. In Durham, at Wassing-
hope lead mine near Stanhope, in small nodules imbedded in sulphate
of barytes. In Scotland, at Wanlock Head, and the lead hills in
Lanarkshire. (Phillips’ Mineralogy, p. 310). Phillips classes this
mineral under the head “ Native Metal and Metalliferous Minerals.”
Modern writers on the composition of colours, call this pigment
Bleu de Montagne — Mountain Blue—Blue ochre of copper.—
Lomazzo mentions the colour under the name Ongaro.a
With regard to the last appellation, Ongaro, Pacheco (p. 373)
relates a circumstance not generally known. “ Philip, Count of
Flanders, ordered Michael Coxis of Malines to make a copy for him,
of the celebrated picture by Van Eyck at Ghent; he copied it ex-
tremely well, and because they could not procure any azure so fine
as that used in the original, they sent to Titian, who was at Venice,
for some of a natural azure, which is found in Hungary, which was
formerly very easy to procure, before the Turks were masters of that
province, and the blue for the drapery of the figure cost thirty
ducats.” Perhaps this was some of the same kind of azure that
Titian desired the Doge to send him (if there were any). This
anecdote shews, that the blue carbonate of copper was used in oil
by Titian, and probably by Van Eyck, since no other blue could
be found in Flanders which matched that in the picture.
a Because it was brought from Kerhausen in Hungary. Marcucci (p. 70) enu-
merates it among the green pigments, a circumstance which identifies it with the
Lapis Armenus which was sometimes blue and sometimes green.