The Book of
Mormon teaches that knowledge of glass was known to the Jaredites (well before the exilic period):
And it came to pass that the brother of
Jared, (now the number of the vessels which had been prepared was eight) went
forth unto the mount, which they called the mount Shelem, because of its
exceeding height, and did molten out of a rock sixteen small stones; and they
were white and clear, even as transparent glass; and he did carry them in his
hands upon the top of the mount, and cried again unto the Lord, saying: (Ether
3:1)
While some
may believe that this is an anachronism, knowledge of glass and glassworking
was known at this time period. In their book on the history of glass, Dan Klein
and Ward Lloyd noted:
Since the Bronze Age, about 3000 BC, glass
has been used for making various kinds of objects. It was first made from a
mixture of silica (from sand), lime and an alkali such as soda or potash, and
these remained the basic ingredients of glass unto the development of lead
glass in the seventeen century. When heated, the mixture becomes soft and
malleable, and can be formed by various techniques into a vast array of shapes
and sizes. The homogenous mass thus formed by melting then cools to create
glass, but in contrast to most materials formed in this way (metals, for
instance), glass lacks the crystalline structure normally associated with
solids, and instead retains the random molecular structure of a liquid. In
effect, as glass cools, it progressively stiffens until rigid, but does so
without setting up a network of interlocking crystals customarily associated
with that process. This is why glass shatters so easily when dealt a sudden
blow, why glass deteriorates over time (a process call devitrification),
especially when exposed to moisture, and why glassware must be slowly annealed
(reheated and uniformly cooled) after manufacture to release internal stresses
by uneven cooling. (Dan Klein and Ward Lloyd, The History of Glass [Tiger Books, 1997], 9)
Elsewhere we
read:
The Late Bronze Age
Although the place and time of the discovery
of glass is uncertain, the earliest known industry Bronze Age by the middle of
the third millennium BC. This industry, first founded in western Asia, probably
in the Mitannian or Hurrian region of Mesopotamia, was the natural outgrowth of
experimentation with vitreous glazes, used to embellish pottery, tiles and
other objects, or with faience. The earliest archaeologically datable objects
are beads, seals, inlays and plaques. Vessels appeared later, probably by the
close of the sixteenth century BC. Shortly afterwards, knowledge of the
manufacture of glass spread quickly to northern Syria, Cyprus, Egypt, and the
late Aegean, where the palace-dominated civilizations of the Late Bronze Age
used glass as a semi-precious material. (Ibid., 14)
On the Jaredite stones themselves, see the following from Book of Mormon
Central: