Diploma (Correspondence) course in gem Identification :-
Duration: 7 month . Can be completed in a shorter period also.
Commences as per candidates convenience.
Course literature is provided along with a set of assignments to be completed and forwarded as per scheduled dates.
Assignment as per scheduled to be submitted before the related practical sessions.
Candidates, who do not forward assignment over a period of six months continuously, will be sent a reminder letter. Those who do not respond within a month will be considered as suspended from the course.
Practical after specific completed topics (12.00 to 5.00 pm.) or on completed of all theory and assignments (20 days-full days)
Dates for the complete practical session can be scheduled at IGTLJ with Two weeks prior notice given in writing.
The Diploma Examination will be held immediately on completion of the practical sessions at IGTLJ, and will follow the examination format as per Regular Diploma course.
Topic to be covered :-
Introduction : Formation of minerals, basic qualities (beauty, rarity, durability), classification of gem materials, weights and measures.
Physical characteristics of gemstone : Hardness, Cleavage, Fracture, Parting, Specific Gravity, Estimation of Heft of a gem material.
Crystallography : Nature of crystal, Elements of symmetry, Crystal System, Forms, Habit, Twinning, Surface markings, Identification of Rough.
Magnification : Inclusions- Their nature and importance in identification.
Optical Characteristics : Nature of light, Electromagnetic Spectrum, Transparency, Light Reflection and Refractive Index and its measurements, Phenomenal effects Chatoyancy, Asterism, Sheen, Aventurescence, Play of colour, Change of colour etc. Reflectivity, Colour and its causes, Pleochroism, Dispersion, Absorption Spectroscopy, Luminescence, Application of Ultra Violet, X-rays and Infra-red rays in Gem Identification.
Other Properties : Electrical and magnetic properties, Thermal Conductivity, Surface Tension & Cohesion.
Instruments Used In Gem Identification : 10xLens, Microscope, Polariscope, Dichroscope, Refractometer, Visible and Spectrometer, Ultra Violet Light, Specific Gravity by Hydrostatic method and liquid immersion, Chelsea Colour Filter, G.M Counter, Hot Point, etc.
Synthetic, Composite and Imitation Gemstones:
Method of synthesis, Stones synthesized, Identification techniques, Characteristics, Manufacturers and trade names.
Gem Enhancement Methods and their Identification : Colourless/Coloured impregnation, Heat Treatment, HPHT, Graphitization, Coating, Irradiation, Diffusion Treatment(Traditional & Beryllium), Foiling & Laser Drilling etc.