i8o 
Count de Bournon’s Description of 
Variety 4. Amianthijorm. 
This variety is composed of fibres as delicate as those of ami- 
anthus, of the flexibility of which they frequently possess a 
certain degree. These fibres are either parallel, or divergent 
from one common centre, in which case they nearly resemble 
a hair pencil. Their colour varies considerably : I have seen 
them of different shades of green, from a grass green to a dark 
brown green, of a golden brown, of a straw colour, of a golden 
yellow, of a greenish blue colour, and even perfectly white, 
having frequently the lustre of satin . 
The fibres are sometimes so delicate, so short, and so con- 
fusedly grouped together, that the whole appears like a dusty 
cottony mass, the true nature of which is discoverable only by 
the lens. At other times, this variety appears in small thin la- 
minae, rather flexible, sometimes scarcely perceptible to the 
naked eye, sometimes tolerably large, and perfectly like ami- 
anthus papyraceus. 1 have seen the last mentioned form of 
this variety, of a light green colour, and also of a very delicate 
white. 
Variety 5. Hematitiform. 
This variety is in layers, either flat or mamillated ; and is of 
a fibrous texture ; but is rendered compact by the close manner 
in which the fibres are united to each other, in the same way 
as is observed in many martial hematites, and more particularly 
in that kind of tin ore which is known by the name of wood- 
tin, to which, some pieces of this arseniate of copper have a 
very great resemblance. Yet it sometimes happens, as in many 
aggregate pyrites of a globular form, that the surface of the 
