OUTES: LA EDAD DE LA PIEDRA EN PATAGONIA. 
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APÉNDICE C. 
SOBRE LOS CARACTERES PETROGRÁFICOS DE LAS RO- 
CAS EMPLEADAS POR LOS PATAGONES, EN LA FA- 
BRICACIÓN DE SUS INSTRUMENTOS Y ARMAS. 
Me parece conveniente transcribir á continuación las observacio- 
nes petrográficas hechas por Rudler, Lovisato y Del Lupo en el 
material arqueológico revisado por ellos y procedente de las esta- 
ciones neolíticas de la Patagonia, 
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OBSERVACIONES DE FE. VW, RUDLER. !* 
«An inspection of Colonel Lane Fox's fine collection of arrow- 
heads «€c., recently brought from the Rio Negro, shows that by 
far the greater number of these objects are worked in siliceous sto- 
nes, such as hornstone, jasper, aud other compact and cryptocrys- 
talline varieties of quartz. For a few of the arrowheads a trans- 
lucent, milky chalcedony has been employed; and in one specimen 
the chalcedony is clouded with brown markings, due probably to 
the presence of oxide of manganese. 
Many of the arrowheads are wrought in different kinds of jas- 
per, which present red, brown, and yellow colours, and are in some 
cases banded, as in the well-known «riband jasper». But the ma- 
terial of which the greater number ofthese objects is composed 
should rather be called hornstone or chert, and in some specimens 
the stone migth almost be taken for ordinary flint. 
Indeed, the mineralogical differences between some of these si- 
liceous stones is extremely trivial. In flint the fracture is eminen- 
tly conchoidal, whilt in chert it is rather more splintery; jasper 
1s distinguished by its opacity, most of the other forms of silica 
being translucent at least on the thin edges; between hornstone and 
' Laxe Fox, £bid, 320 y siguiente. 
