SANDASTER : Aventurine (?), Matrix of Opal (?).
A gem so
called from the locality in India that produced it; sometimes also
known as the Garamantica, because coming from the interior of Africa.
It was likewise found in Southern Arabia. It is described by Pliny as
related to the Anthracitis (a substance like fossil charcoal, and
probably Jet) ; but its value consisted in the circumstance that a fire
shone forth inclosed within it, with golden drops glittering like
stars, and these last always confined within the substance of the
stone, not showing upon its exterior, (xxxvii. 28.)
these data De Laet, and most mineralogists after him, pronounce the
Sandaster to have been our Aventurine (then newly brought from India),
a reddish-brown translucent quartz, filled with innumerable particles
of goldlike mica. It takes its present name from the fact that the
Venetian imitation of it, so often seen in Italian jewelry, as a ground
for mosaics, and in earrings, brooches, &c, was found out per aventura, " by good luck ; " from the accidental admixture of brass filings with melted glass.
But the innumerable specks of gold, the chief beauty of the Aventurine, prove of themselves that this was not the Sandaster : because
the latter was held a sacred gem, as bearing an affinity to the
heavenly bodies, on account of the stars within it being arranged as
the constellation the Hyades stand in heaven, and in the same
number—that is, only five. Besides, the golden specks in the Aventurine