East and West in ancient and medieval times.
However, in Kitah al-Jamahir, Beruni reports by referring to and
quoting al-Kindi (about 803—871) as seeing a brilliant blue turquoise
stone weighing about one and a half ounce. Other stones are reported
to have other colours tinged in green, yellow and brown.
Quartz, Crystals and Glasses
Among the quartzes are agate specimens that are reported in several
hues and opaque colours; yellow, red and blackish, agate is found in
varieties of silicon dioxide. It is considered among the commonest of
the mineral species in the earth's crust. Rapid depositories often gather
and fill alcoves and rocky grottoes with beautiful, varicoloured bands
and patterns of extremely fine-grained agates.
Quartz is generally regarded in modern geological studies as a
crystalline mineral, a form of silica, usually colourless and transparent.
Again, it is the commonest material found in the cavities of geodes,
sphere-shaped sparkling stones, partially hollowed with lining cavities of
concentric mineral crystals and layers.
Onyx is also one of the quartz varieties used for cabochons, carving
and art objects known since antiquity. Onyx and other gemstones are
mentioned in Holy Scriptures. In its opaque appearance, it shows even
bands or layers with a dark black tint as well as white colouring as also
referred to by Beruni. Moreover, onyu in its structure is considered
hard enough stone that takes and retains a high polish, yet too hard to
be cut and engraved.
Several excellent specimens of onyu have been reported in the
literature, and discovered in many parts of the globe from Arabia to
Ethiopia, and from India to the New World. Objects from stalactitic
onyx banded and patterned in tan, brown and yellow are found in limestone caves. Indeed onyx crystals were observed, defined, measured
and their patterns investigated by Beruni about six centuries before
Johannes Kepler and Nicolaus Steno. The latter described in particular
onyu formation, patterns, and its chemical and physical properties and
virtues. He established, in 1669 A.D., an expression of a natural law
based upon the constancy of interfacial angles, a law that has remained
valid to this day concerning the science of crystallography. Onyx's
remarkable structural arrangement and design, precision, exceptional
beauty and symmetry have the highest and finest expression ever in
its kind.40
Crystals, known as the ice or frost thing, are verbally derived from
the Greek kryos-tallos to mean ice-cold. In Arabic, the author defines
it as ballur or billur, i.e., the air-water quartz combination. It is manufactured from finest glassware and ornaments — objects that were
