NIDG
NATIONAL INSTITUTE OF DIAMOND & GEMS
"AN ISO 9001: 2008 CERTIFIED"
(GOVT. Registered)



Gemology


Diamond Identification & Grading Course


COURSE - I (2 Months)

  •     Part A — Introduction
  • What is a diamond ?
    The world's most famous diamond

  •     Part B — Diamond
  • Defination & properties
    Formation
    Mine exploration
    a) Exploration of a pipe mine
    b) Extraction

  •     Part C - Cutting & Polishing
  •     Part D— The value of diamond & the 4c's
  • Carat Weight

    a) Diamond weight estimation formula
    b) Diamond weight estimation of round brilliant with normal proportion

    Clarity

    a) Clarity characteristics
    b) Plotting
    c) Clarity grading

    Color

    a) Diamond types
    b) Normal color range
    c) Fancy color
    d) Artificially colored diamond

    Cut

    a) Proportions
    b) Measurement
    1) Round brilliant cut
    2) Fancy shapes
    c) Estimating propartion
    1) The crown angle
    2) The table
    3) The crown height
    4) The pavillion depth
    5) The girdle thickness
    6) The culet terminology
    d) The proportion grades

  •     Part E — Finish
  • 1) The polish
    2) The Symmetry

  •     Part F — Simulants & Synthetics
  • a) Summary of the most important
    diamond & imitation's characteristics
    b) Synthetic diamond
    1) Main producer
    2) Production methods
    3) Identification

  •     Part G - Clarity treatments & Laser Inscriptions

  • Color Gem Stones Identification


    COURSE - II (2 Months)

    • Part A
    • • What is gemology
    • • What are gems
    • • Nature of minerals ( crystallization)
    • • Polishing of gemstones
    • a) Cutting
    • b) Scintillation
    • c) Tumbled stones
    • d) Various cutting styles
    • • Light & color
    • Part B
    • • Light & refractometer
    • a) Reflection
    • b) Refraction
    • c) Luster
    • d) Total internal reflection
    • e) What is brilliance ?
    • f) Dispersion & fire
    • g) Double refraction
    • • Refractometer
    • a) Measuring of refractive index
    • • Light & polariscope
    • a) Polarized light
    • b) Polariscope
    • c) Use of polanscope
    • • Light & spectroscope
    • a) Emission & absorbtion
    • b) The spectroscope
    • c) Some important spectra
    • • Light & microscope
    • • Dicroism & the dichroscope
    • • The chelse a color filter
    • • Specific gravity
    • • Fluorescence
    • • Optical phenomena
    • Part C
    • • Inclusions ( corundum , beryl , garnets , zoisite, opal , spinel, zircon , topaz, chrysoberyl, feldspar, spodumene etc)
    • Part D - Synthetics
    • • The production of synthetics
    • a) Introduction
    • b) Method to produce synthetic gemstones ( flame fusion, pulling floating zone , skull melting, flux, hydrothermal
    • • Synthetics from other process (ceremic, sublimation, etc)
    • • Identification of synthetics
    • • More of practical studies
    • Part E - Treated Gemstones
    • • Intro
    • • Thermal treatments
    • • Irradiation
    • • Staining
    • • Bleaching
    • • Coating
    • • Impregnation
    • • Fracture filling
    • • Laser drilling
    • • Doublet & triplets