Gem identification course is a basic introduction to the world of gemology and gives firsthand knowledge considering the heavy demand from the industry and general public. Surya institute of gemology has designed short term courses for Gem identification with all basic gem testing instruments, treatments, as well as further education courses in gemmology. These include advance instrumentation courses etc.
Key areas of exposure:
- Introduction to gemology identification system basic qualities; chemical composition; weights and measures.
- Crystallography: nature of crystals; systems of crystallography; crystalline and non-crystalline materials; forms; habit; twinning.
- Physical properties: hardness; cleavage; special gravity (heavy liquids and hydrostatic method).
- Optical properties : colour; transparency; visible spectrum; light reflection; total internal reflection; single and double refraction; dispersion; polarization; refractive index and its determination by refractometer; reflectivity; reflectometers.
- Colour and causes of colour : Pleochroism; interference; lustre; sheen; opalescence; Adularescence; iridescence; asterism; chatoyancy.
- Instruments used for gem identification: jeweller’s lens; microscope; spectroscope; dichroscope; Chelsea colour filter; ultraviolet light and x-rays; polariscope; refractometer.
- Synthetics, man-made and imitation gemstones and plastics: different methods of manufacture; characteristics; identification.
- Occurrences of gemstones: geographical origin of gemstones is an important aspect in the assessment of quality of gemstones especially rubies, sapphires ,emeralds and diamonds
- Fashioning of gemstones: procedures, processes and equipment used in cutting of Gems stones. Different styles of cutting. Grading gemstones depend on their quality.
- Treatment of gemstones: dyeing, coating, heat treatment, irradiation, waxing, fracture filling, oiling, laser drilling, hpht and other treatments.
- , diffusion, glass filling, with different methods of gemstones identification.
- Marketing aspects : gem & jewellery industry an overview, analysis of prospects and problems of various sectors such as precious/semi precious Gemstones , diamonds, pearls, synthetic, imitation, jewellery studded and plain gold.
Practical’s knowledge & experience:
Practical knowledge is most important part of our gem identification course. This gives hands on experience for each and every student who completes their theory classes and go through various paper work and exercises with various Gem stones.
Observation of external features (cut, shape colour, clarity, transparency, luster, polish of the Gemstone, brilliance and fire of the Gem stone etc.) Of a gemstones using a 10x lens.
- Observation of external symmetry, surface marks and cleavage of various inclusions, crystals and their identification.
- Determination of specific gravity by hydrostatic weighing method and by using heavy liquids.
- Measurement of refractive indices and birefringence tests using a gem-testing Refractometer.
- Detection of double refraction, interference figures and internal strain with the Polariscope.
- Detection of double refraction, by observing pleochroic colours with the dichroscope and 10x lens. Identification of gemstones on the basis of pleochroic colours.
- Study of the absorption spectra of various gemstones using a direct vision spectroscope.
- Study of the fluorescent colours exhibited by various gemstones under ultraviolet (long wave and short wave) light.
- Observation of the internal features of various natural and synthetics gemstones with a microscope.
- Use of colour filters in detecting synthetic gemstones;
- Identification of unknown gemstones using the above techniques. During the course each student individually practices and handles hundreds of gemstones.
- Detection of treatments on gemstones.
- Determination of origin of gemstones.
Every student has to undergo the following examination system to obtain credits
- Theory Part – 100 Marks ( Pass with 70 marks )
- Practical Part – 100 Marks ( Pass with 100/100 marks )