Corsi Collection of Decorative Stones

Class X
Puddingstones (Pudinghi)

The hard breccias are different from the calcareous breccias both in the shape of the fragments and in their constituent substances. They contain many fragments, generally round, of various colours, and of a siliceous nature. The cement enclosing them is sometimes compact limestone, and often feldspar, for which reason they are very hard to cut and take a beautiful polish. The English call them puddingstones, because of their resemblance to a dish to which they give the name of pudding, which was changed to 'Pudingo' by the Italians.

Modern geologists distinguish breccias from conglomerates by the shape of the clasts; rounded pebbles in a conglomerate and angular fragments in a breccia. The term 'puddingstone' is now restricted to certain siliceous conglomerates traditionally called by this name, for example the English 'Hertfordshire puddingstone'.

Some geologists in Corsi's time were classifying clastic sedimentary rocks according to their principal mineral constituents – calcite or quartz – and others according to the size and shape of the fragments. This posed particular problems for Corsi, who chose to organise his collection according to mineral constituents. He treats all his breccias as calcareous rocks and classes them as a variety of marble, but by the time he reaches puddingstones in his classification, he is clearly uncertain whether they are so called by virtue of their shape or mineral content, and conflates the two in his introduction. In practice, many of his so-called puddingstones are calcareous conglomerates, and rightfully belong with his marbles.

§ I Ancient puddingstones (Pudinghi antichi)

Varieties

679. (162.1) Breccia verde d'Egitto. This is the most beautiful puddingstone that is known because it contains in it many fragments of porphyry, granite, [p163] and quartz of different colours enveloped by compact feldspar. The glue uniting the fragments is always green, and the fragments themselves are frequently of the same colour. Because so many stones are united in the one stone, this puddingstone has acquired the name of universal breccia (breccia universale). The ancient quarries were in Upper Egypt, and precisely in the valley of Quosseyr (Brard 97 ). The most beautiful pieces to be seen in Rome are a large tazza, and two half-columns in the Villa Albani, and the magnificent column-base in the Palazzo de' Conservatori on the Campidoglio. (Very rare).

Brard i describes this stone: 'Poudingue granitique et porphyritic de la vallée de Qosseyr, dans la Haute-Egypte. (Breccia verde d'Egitto des Italiens, vulgairement Brècche d' Egypte ou Brèche universelle).' Brard continues with a description of the constituents of this stone, based on information from M. Rosière at the Institut d'Egypte, and then gives some of its uses.

Corsi uses the word glutine rather than cemento. 'Glue' means any binding substance that sets hard and brittle just as the 19th century animal glues used to, and so it may be the more literal translation. However, as modern glues are no longer thought of in that way, 'cement' would be a more usual rendering here, as in Dolci ii . Geologists use the term 'matrix' for the cement that binds the fragments or pebbles in a breccia or conglomerate.

i. Brard (1821) vol. 2, 250-253
ii. Dolci & Nista (1992) 80

680. (163.2) Grey ground with white, pinkish and yellow fragments spotted with black. Very beautiful, and (very rare).

This is the true breccia frutticolosa to which Corsi i refers in the third edition of his Delle Pietre Antiche. It was used from late Roman times through the Baroque era. The quarries have been rediscovered in recent years at Bourdeau, in Savoie, France ii . The distinctive 'holes' in the pebbles are where bivalves bored into the sediments while they were still relatively soft.

See no.415 for the stone that Corsi originally thought was breccia frutticolosa.

i. Corsi (1845) 200
ii. Price (2007) 146

681. (163.3) Green ground with red and faded yellow fragments. (Very rare).

682. (163.4) Grey ground with very small fragments of white, black, green, and dark blue. (Very rare).

[suppl.p23]

968. (Suppl.23.1) Breccia d'Egitto. Coffee-coloured ground with markings of dark green. (Rare).

969. (Suppl.23.2) Another made up of various greens, and with a large marking of rose-coloured granite. (Very rare).

[p164]

§ II Italian puddingstones (Pudinghi d'Italia)

683. (164.1) Traccagnina delle Alpi. Deep peachy coloured ground with small fragments of grey, purple, and black. (Rare).

684. (164.2) Breccia delle Alpi. Light red with fragments of darker red. (Rare).

685. (164.3) Breccia delle Alpi. Dark greenish ground with fragments of blush pink and purple. (Rare).

686. (164.4) Breccia delle Alpi. Peachy coloured ground with white, grey, and purplish markings. (Rare).

687. (164.5) Breccia delle Alpi. Dark grey ground with red, and white, markings. (Rare).

688. (164.6) Breccia delle Alpi. Light green ground with fragments of whitish and peachy colour. (Rare).

689. (164.7) Breccia delle Alpi. Dark green ground with fragments of white and purple. (Rare).

690. (164.8) Breccia di Sicilia. White ground with large and very small fragments of black and bluish grey. (Very rare).

[p165]

691. (165.9) Breccia di Torrita, near Rome. Deep grey ground with fragments of light grey, and faded yellow. Half this specimen is of the very beautiful alabastro d'Orte. (Very rare, and perhaps unique).

692. (165.10) Breccia di Roma. Dark grey ground with long fragments of a yellow colour, grey, white, and purple. The white and the yellow ones are dendritic. It is found in the neighbourhood of Ponte Salario. Very beautiful and (rare).

693. (165.11) Breccia di Roma. Purplish ground with round fragments of white, yellow, grey, and the colour of raw meat. (Rare).

694. (165.12) Breccia di Roma. Ash-coloured ground with round fragments of white, yellow and grey in various shades. (Rare).

695. (165.13) Breccia di Perugia. Dark ash-coloured ground with greenish, black, white and grey fragments. (Very rare).

696. (165.14) Breccia di Roma. Light peachy colour ground with very tiny fragments of white, grey, purplish and yellow. (Very rare).

697. (165.15) Breccia di Roma. Light grey [p166] ground with half the fragments of white, and [half] of peachy colour. (Rare).

698. (166.16) Pudingo delle Alpi. Peachy coloured ground minutely brecciated with white and red. (Rare).

699. (166.17) Pudingo delle Alpi. Grey ground that shades into light green, brecciated with white, red, and dark blush pink. (Rare).

[suppl.p23]

970. (Suppl.23.1) Pudingo di Sabina, with very tiny breccie of white, and various shades of reddish. (Common).

971. (Suppl.23.2) Pudingo di Toscana. Dark grey ground spotted by red, white, yellow and green. (Rare).

972. (Suppl.23.3) Pudingo delle Alpi. Dark green ground with markings of red, white, grey and green in various shades. Very beautiful, and (rare).

[p166]