The ancients placed a high value upon the asteria, which
they regarded as a powerful love-charm and for this purpose,
according to tradition, it was worn by Helen of Homeric fame ;
so, then, to this beautiful gem were due all the calamities of
the Trojan war. Very fine specimens of the star-sapphire are
found in the collection of the Ecole des Mines, and an extraordinary asteriated diamond at the Jardin des Plantes.
The term girasol, like asteria, is applied to certain gemstones peculiar in structure, rather than as a variety of a
particular species. The name, signifying "to turn to the sun,"
was given to it on account of the remarkably radiant light it
emits when exposed to the solar rays, which moves as the
stone is turned in different directions. The opal girasol
possesses this quality in a higher degree than the sapphire
specimens. The largest known girasol, called the Ruspoli, of
one hundred and twenty-three carats weight, now in the
Museum of Mineralogy, Paris, was found in Bengal and sold
for thirty-four thousand dollars.
Ruby. — It is supposed the ruby corresponds to the anthrax
of Theophrastus, and the lyciinis of Pliny, one of the species of
stones to which he gives the general appellation carbunculus.
Both its Greek and Latin names were conferred in reference
to some characteristic quality, as anthrax (red coal), in allusion
to the color, and lychnis to its capacity of becoming very
brilliant by lamplight. Its modern name ruby, rubino (red),
is only an epithet for the red corundum, or red sapphire.
The ruby has the same chemical composition as the sapphire, pure alumina, with a difference of coloring matter, and
ranks next to it in hardness. It possesses double refraction,
exhibits electric properties, and, like the sapphire, its crystals
are double six-sided prisms. The color varies from a rose
to the deepest carmine, but the most approved tint is that of