Among the white stones also, there is one known as "ceraunia,"[1] which absorbs the brilliancy of the stars. It is of a crystalline formation, of a lustrous azure colour, and is a native of Carmania. Zenothemis admits that it is white, but asserts that it has the figure of a blazing star within. Some of them, he says, are dull, in which case it is the custom to steep them for some days in a mixture of nitre and vinegar; at the end of which period the star makes its appearance, but gradually dies away by the end of as many months.
Sotacus mentions also two other varieties of ceraunia, one black and the other red; and he says that they resemble axes in shape. Those which are black and round,[2] he says, are looked upon as sacred, and by their assistance cities and fleets are attacked and taken: the name given to them is "bætyli," those of an elongated form being known as "cerauniæ."[3] They make out also that there is another kind, rarely to be met with, and much in request for the practices of magic, it never being found in any place but one that has been struck by lightning.[4]
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