In
France it is found in a cavern near Menât, in Alvernia. Bomarè says
that there the banks of this substance are arranged from east to west,
and covered with 3,898 mètres of earth. He adds that tripoli found
there is rather soft, but hardens by contact with the air.
XCVII.
TURQUOISE.
The Venetians, who were the first to bring this gem into Europe from Turkey, called it turchesa, and afterwards turquina. Turquoise is of three kinds, viz., aluminous Oriental turquoise, fossil or osseous Oriental turquoise, and Western turquoise.
The
aluminous Oriental turquoise is found in the alluvial lands of India
and Persia in globules disposed in lines, or in small fragments. It is
of a beautiful sky blue colour, sometime*« slightly spotted with green.
It is less hard than quartz, but scratches glass, and yields to a good
steel file. Nothwithstanding its opacity, it takes a beautiful 'polish.
It
is insoluble in azotic acid ; and thus it is easily distinguishable
from the other kinds. Its specific weight is 3.127. On analysis it gives
