confusion was perpetuated by rendering the Greco-Latino name of the stone common, and it was called, indifferently, prasma, plasma, or the matrix of the emerald.
I have explained above which is the stone that properly claims the name of plasma ; that which I call prase
(or prasina) is now acknowledged to be the matrix of the emerald : this
can be proved by observing how the pieces anciently used, of-this
substance, are identical with the prase which was taken from the
emeraldiferous mines of America.
Prase is still found in Saxony, Bohemia, Finland, Scotland, and Siberia.
The brittleness of the prase prevents it being engraved.
I
have seen an immense number of ancient pierced " margherite " in prase,
but I never saw any pieces engraved. I tried to cut some, but they
broke under the trial.
LXXXIV.
QUIRITINE.
By this
name Ceselli denoted a mineral composed of silex, alumina, soda, lime,
protoxide of iron, and traces of magnesia ; it was found by him on
Mount Lazuli in 1856.
