474 KEPORT ON NATIONAL MUSEUM, 1886. 



of tliese in tbe Museum collection show the prevailing colors to be dark 

 olive green with veins, streaks, and blotches of greenish white, clioco- 

 late brown, and blood red. The green varieties are often spotted by 

 ill-defined Hakes of a " silky brouzitic mineral." 



The rock is softer than the serpentine of Harford County, Md., but 

 takes an e(iually good surface and polish, and works much more readily. 

 It is stated by Hull * to be obtainable in blocks from 7 to 8 feet in 

 length and from 2 to 3 feet in diameter. According to this same au- 

 thority, the stone is admirably ada])ted for interior decorations and is 

 now being used for ornamental fonts, pulpits, small shafts, and pilas- 

 ters, as well as for vases, tazza, and inlaid work. 



Considering the remarkable beauty and the variety of colors dis- 

 played by this stone, it seems strange that it should not have found its 

 way more extensively into Ameri(;an markets. 



The rock is regarded by Bonueyt as an altered intruded igneous rock, 

 rich in olivine (Lherzolite). 



Italy. — The principal sorpentinous rocks of Italy are the ophicalcites 

 of Pegli and Pietra Lavezzara, near Genoa, and of Levante, and the true 

 serpentine of Tuscany. The Yerde di Pegli is a breccia cousistiug of 

 deep green fragments of serpentine cemented by light green calcite. 

 The contrast of colors thus produced is said to be very pleasing. The 

 Verde di Genova stone from quarries at Pietra Lavezzara is also a 

 breccia consisting of green, blackish green, brown, or red serpentine 

 fragments with an abundant cement of white or greenish calcite. It 

 has been quarried from time immemorable and is largely used in France 

 where it is known as Vert de Genes. Its selling price at Turin is about 

 20 cents per cubic foot. The opliicalcite of Levante is a breccia like the 

 preceding, the fragment being of a violet or wine red color. It is diffi- 

 cult to work but acquires a good polish. The Italian name for the stone 

 is rosso or Verde di Levante ; tliough sometimes called (jranito di Le- 

 vante. The Tuscany seri^entine from quarries near Prato is known com- 

 mercially as Verde di Prato. The stone is of a deep green color, carry- 

 ing crystals or nodules of diallage and is traversed by a net-work of 

 fine lines giving it a brecciated appearance. It contains also veins of 

 noble serpentine of a clear, greenish or whitish color. It is softer than 

 ordinary serpentine and acquires only a dull polish, but works very 

 readily. The dark green varieties are most valued, and having been used 

 in ancient monuments is frequently called the Nero antico di Prato | 

 This stone is stated by Hull to be subject to rapid decay when exposed 

 to atmospheric influences. 



* Building and Ornanientiil Stones, p. 102. 



t Quar. Jour. Geological Society of Loudon, Vol. xxxiii, Part 2, 1877, p. 884. 



t Delesse, pp. 77-79. 



