CHAP. 48.—ASTRION.
Of a similar white radiance is the stone that is known as
"astrion," [Note] closely resembling crystal in its nature, and found
in India and upon the coasts of Pallene. [Note] In the centre of it
there shines internally a brilliant star, with a refulgence like
that of the moon when full. Some will have it that this stone
receives its name from the fact that, when held opposite to the
stars, it absorbs the light they emit and then returns it. The
finest stones, they say, are those of Carmania, there being
none more entirely free from all defects. They add, also, that
a stone of inferior quality is known as "ceraunia," [Note] and that,
in the worst of all, the light is very similar to that given by a
lamp.