Gemology or gemmology is
the science dealing
with natural and artificial gemstone materials.
It is considered a geoscience and
a branch of mineralogy.
Some jewelers are
academically trained gemologists and are qualified to identify and evaluate
gems.
Gemstones
are basically categorized based on their crystal structure, specific gravity, refractive index,
and other optical properties, such as pleochroism.
The physical property of "hardness" is defined by the
non-linear Mohs
scale of mineral hardness. Gemologists study these factors while
valuing or appraising cut and polished gemstones. Gemological microscopic study
of the internal structure is used to determine whether a gem is synthetic or
natural by revealing natural fluid inclusions or
partially melted exogenous crystals
that are evidence of heat treatment to enhance color.
The
spectroscopic analysis of cut gemstones also allows a gemologist to understand
the atomic structure and identify its origin, which is a major factor in
valuing a gemstone. For example, a ruby from Burma will have definite
internal and optical activity variance from a Thai ruby. When the gemstones are
in a rough state, the gemologist studies the external structure; the host rock
and mineral association; and natural and polished color. Initially, the stone
is identified by its color, refractive index, optical character, specific
gravity, and examination of internal characteristics under magnification.
Gemmology In Ancient India
Gemmology, the
science of gems, despite its having a commercial aspect, is a subject of
absorbing interest to one and all alike. In Sanskrit, a precious stone is known
by the name ratna, a term which denotes an object of delight or a coveted
object. Precious stones are treasured not for their beauty and value alone but
for their magic efficacy on the person as well, since some germs are used in
components of medical preparations, while all gems have their curative
faculties in psychic therapy.
From very
ancient time, knowledge pertaining to gems was widespread in India, which is
well-known as a source-spot of various types of precious stones. In course of
time, the entire knowledge was systematised and given the status of Sästra or
science. We find innumerable data pertaining to gemmology lying scattered in the
vast expanse of Sanskrit works. India is well-known as a source-spot of various
types of precious stones. From the past several centuries, our country is
renowned as one of the greatest trading centres for precious stones. The vast
mass of our ancient literary works contains hundreds of allusions to precious
gems which throw light on the fact that from very ancient time, knowledge
pertaining to precious stones was widespread in ancient India. In course of
time, probably, the entire knowledge was systematised and given the status of
"ästra' or science which became popular by the name 'Ratnafästra'. Of
course, ancient Indians were well-known for their cultivating any branch of
knowledge as an independent science and studying the same in a systematic manner.
Ancient Works On Gemmology
We come across innumerable data pertaining to gemmology lying scattered
in the vast expanse of ancient Sanskrit literature. Kau!ilya has mentioned
'Ratnaparihä' (Gemmology) in Arthafästra while Vätsyäyana has included the same
in the list of 64 subsidiary arts (Kämasütra,). Vyäsa, Agastya, Aigirasa,
Varähamihira and a host of sages and great writers of ancient India are
mentioned as having composed works on Ratnafästra. Apart from ancient works
like 'Ratnafästra', 'Utpalaparimala', 'Vähata', Candesvara's 'Ratna Dtpika' and
Buddha Bha!!a's 'RatnaSästra', several other compilations like ViSvakarmiya,
Smgisärasahgraha, Brhatsahlhitä, Yuktikalpataru of Bhoja Deva, Manasolläsa of
Somadeva and Sivatattvaratnäkara of Basava Bhüpa also contain sections giving
detailed accounts of gems. Sukra Niti, Agnipuräpa, Skandapuräea (Häläsya
Mähätmyam in Agastya Sapphitä), etc. supply very useful information pertaining
to precious stones.
Generally, these works on gemmology
contain sections dealing with legendary stories related to the origin of
different gems, their source-spots and mines, characteristic features like
colour, density, weight, etc., flaws and defects, method of weighing,
evaluation, good or bad effects of wearing flawed gems, different varieties of
each gem, etc. Like many other Hindu branches of learning, the science of gems
is also interlinked with a good deal of mythological and legendary lore.
Different legendary versions are given about the origin of gems which only
serve the purpose of glorification of gems. Despite this, we come across many
verses in these treatises which prove that ancient Indians were in possession
of the knowledge that gems are stones caused by the nature of special types of
rocks.
Geologists of modern times have
observed the physical properties of gem-stones, viz., cohesion, hardness,
specific gravity, transparency (ability of a substance to transmit light),
lustre (appearance of a stone in reflected light), sheen (reflection from
within the stone), etc. Gemmologists of ancient India have noticed and have
examined the above-mentioned physical properties of each and every gem.
Density, spectrum, refractive index, weight, microscopic examination of lines,
bubbles, etc., minutest difference in colour, etc., were the main factors in
identifying different gemstones.
The gems enumerated in Hindu texts are of mineral origin, while a few
like pearls and corals are of animal origin. Hence, a thorough knowledge of
gemmology requires at least some fundamental knowledge of mineralogy, geology,
botany and zoology. The scientific achievements of our ancient ancestors in all
fields of knowledge are well known. The foregoing study also reveals that from
the early period, knowledge of gemmology also was of a very high order and scientific
methods were followed in collecting, testing, cutting and polishing gems.
Professional Gemmology Programs
Course
Content:
·
Application of scientific concepts to
gemmology
·
Chemistry & atomic structure of minerals
·
Refraction, birefringence, dispersion, causes
of colour, luminescence, optical effects in gemstones
·
Crystallography
·
Mineralogy & geology
·
Techniques for testing and characterization
·
Synthetic gemstones and gemstone enhancement
(including diamond)
·
Gem Species (including non-mineral gems,
common gemstones and many lesser known species)
-
nature & properties,
-
formation, locality of origin
-
quality factors & evaluation (including
diamond)
·
Refractive index measurement
·
The spectroscope, gem spectra
·
The microscope and inclusions
·
Practice with instruments
·
Identification of gemstones, synthetics,
simulants and enhanced stones
Diamonds And Diamond Grading
Duration
of the course is 2 ½ months. The course
provides comprehensive knowledge about Diamonds in all aspects. You will be
confident to evaluate Diamonds on lines of the International Diamond Grading
System and the famous 4Cs -Carat, Colour, Clarity & Cut. A balanced
teaching theory & practical grading of actual diamonds will give a unique
experience and a clear understanding of the product.
Coloured Gemstone Identification
Duration of the course is 3 ½ months. The
student is taken into the fascinating world of gemstones by practical training
on identification of a huge variety of real coloured gemstones from all over
the world. The laboratory is equipped with professional gem testing instruments
on which you will learn the identification of coloured gemstones, distinguish
between synthetic/imitation/treated and real gemstones and also learn about
occurrence of gems, their inclusions and optical characteristics.
Practical Gemology goes one step further, explaining how to use the tools of
gemology & processing information supplied. This is the essence of Gem
Identification.
DIPLOMA IN GEMOLOGY
Duration of this course is 6 months. Is a
science, art and profession of identifying and evaluating of gemstones and
diamonds. It is designed to open doors to the vast subject of Gemstones and is
divided into two courses as under
Diamonds and Diamond Grading
Coloured Gemstone Identification
The above will
round off the students education in Diamonds & coloured stones to make
him/her a real gemology professional. These courses can be availed individually
or as comprehensive Diploma in Gemology.
