It possesses double refraction in a very nigh degree.
Its cleavage resembles that of the diamond.
Besides
the jargoon of Ceylon, there is the inferior or Western stone, which is
found in the Trapp rock, near Lisbon ; in the masses of sienite in the
county of Galway ; at Expailly in France ; at Leonedo in the province
of Vicenza, and in the auriferous sands of the shifting district of
Lombardy.
Since
jargoons of a large size are seldom found, those in commerce acquire a
certain price, although never extravagantly high. A very fine pure
olive jargoon, of -012 mètres square, is worth 100 lire ; one less
pure, of another colour yet of equal size, costs 25 lire.
