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194 Star Stones.
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transverse
section of a hexagonal pyramid is made, these lines are seen as
triangular strias From each set of parallel lines a narrow transverse
luminous band is reflected, and the crossing of these three bands of
light produces a star of six rays. Occasionally a secondary system of
lines is apparent, thus giving rise to a twelve-rayed star. Great skill
is required on the part of the lapidary in dealing with such stones to
produce the most effective result.
Although
the majority of Asterias are Sapphire, the same optical phenomenon is
occasionally exhibited by other gems. The purple and reddish Corundums,
when judiciously cut, shew Asterism, thus forming Star Rubies ; and in like manner we may have Star Emeralds and Star Garnets.
The
Orientals have ever entertained a peculiar veneration for Star Stones,
but only of late years have they been of any value in England. The
finest Star Ruby lately seen was valued at £200. The price of these
gems is mainly determined by quality and colour ; small Star Sapphires
range from £2 upwards. Star Rubies obtain higher prices ; but Star-stones, of a secondary rank, are of little value.
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