History & Introduction
Peridot is a gem-quality from the range of olivine. It is derived from the forsterite-fayalite
mineral series. Peridot is considered to be a dichromatic gem that means the color
comes from the basic chemical composition of the mineral itself and not from minor
traces of impurities. In fact peridot is only available in green color. Even though
the shades of green may vary from light yellowish to dark brownish-green.
The history of Peridot is intrinsically tied to the tiny Egyptian island of St.
John (Zabargad) in the Red Sea, which was tend to be the only ancient sources of
gem Peridot. In fact Peridot is both a day and a night stone, making the shining
color even under artificial lighting. Due to this reason, it is sometimes called
"Evening Emerald".
The name 'peridot' actually came from the Arabic word for gem - 'faridat'. Sometimes
it is referred as 'the poor man's emerald' or as 'chrysolite', a word derived from
the Greek word 'goldstone'. It is one of the oldest known gemstones, with date as
early as 1500 B.C. Historically, the volcanic island of Zabargad (St. John) in the
Red Sea, east of Egypt contains the most important deposit that was exploited for
over 3500 years. At present, the finest quality peridot comes from Mogok in Burma,
still, the Pakistani peridot is now highly regarded as well. Different other important
sources available are in Arizona, China and Vietnam. The gemstone has also been
discovered in fallen meteors and it has also been discovered on Mars and the moon
in olivine form. Peridot is the birthstone of August.
Recognise - Peridot is an iron magnesium silicate and the power
of color depends on the amount of iron it carries. However we could find few traces
of nickel and chromium present. Peridot is not that hard and it has no resistance
to acid. Very rare, peridot seems to be known to form with cat's eye chatoyancy
(asterism) in the form of four ray stars. Many times Peridot is confused with similar
colored gems, but its strong double refraction is frequently a very distinguishing
trait. Stones that are thick the doubling of lower facet edges is seen by seeing
down though the table without the need for magnification.
Availability - Most gemstones are formed in earth's crust, however
peridot is formed much deeper in the mantle region. The formation of Peridot crystals
is in magma from the upper mantle and are brought to the surface by tectonic or
volcanic activity where they are found in extrusive igneous rocks. Historically,
Zabargad (St. John), the volcanic island in the Red Sea was the location of the
most important deposit.
Currently, the important deposits are found in Pakistan (the Pakistan-Afghanistan
border region and in the Kashmir region). Beautiful material is also found in upper
Myanmar (Burma) and Vietnam. Other deposits are found in Brazil (Minas Gerais),
Australia (Queensland), China, United States (Arizona and Hawaii), Kenya, Mexico,
Norway (north of Bergen), Tanzania, South Africa and Sri Lanka. Lately, China tends
to become the largest producers of peridot.
Usages - Peridot gems are usually small, though large flawless
stones are rarely cut. Peridot is a common as well as affordable gemstone. It is
faceted into many cuts, and is used in all forms of jewelry, especially rings, necklaces,
earrings, and bracelets. Beads of tumbled Peridot beads and cabochons are also fashioned
in bracelets and necklaces. Peridot is a stone of lightness and beauty. Peridot
should be used by spiritual or clear-minded persons.
Buying Guide
Color - Peridot is among the few gemstones that is available in
a single color. The level of iron content in the gemstone is responsible for the
depth of green. The color of Peridot vary from yellow-green and olive to brownish
green and gives an excellent look in natural daylight. In artificial light the vivid
green color does not change. The best colored peridot has an iron percentage of
less than 15% and naturally some trace elements of nickel and chromium are added,
which contribute to its color. A deep and strong green colored peridot is considered
the most demanding and the most valuable.
Clarity and Lustre - Peridot is available with excellent transparency.
Eye-clean specimens are abundant, however larger stones may appear slightly cloudy
because of the presence of inclusions and impurities. When cut and polished, peridot
consist of an attractive, vitreous luster and greasy.
Cut and Shape - Peridot is faceted naturally because of its excellent
transparency. Table along with step cuts are very famous, as well as unconventional
checkerboards. Peridot can be found in various shapes that includes fancies and
traditional ovals, rounds, emeralds (octagons) and cushions.
Treatment - Peridot is not treated typically or enhanced in any
sort. However, there are reports of metal-foiled peridot that helps to increase
stability along with the paler stones that may be coated with green foil to improve
the color. Imitation peridot are also found.
Gemological Characteristics: