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



COLOR GEM STONES IDENTIFICATION

COURSE - III

  • 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