Our Core Services

Our Core Services

Certification is the main facility at JGL, which broadly issues two types of reports:

  • Identification of Gemstones
  • Hallmarking (Metal Testing)

Each and every stone under test is examined by two or more Gemmologists/Graders independently, first using the standard gemmological equipment, and then by scientific methods using sophisticated spectrometers. Therefore, every report issued is based on vast gemmological experience of the Gemmologists/Graders along with scientific facts.

The report format however varies depending on the type of category under which the certification has been carried out.

Forms Accepted for Identification Reports

Identification reports are issued for gemstones submitted in the following forms:

  • Loose Rough Stones

    Well-formed crystals or broken fragments, with or without polished surfaces, ranging from transparent to opaque.

  • Loose Cut Stones (Any Style)

    Including pre-forms, faceted stones, cabochons, and beads (drilled or undrilled).

  • Set in Jewellery or Decorative Pieces

    Stones mounted in open-back or closed-back settings.

  • Carvings

    Gemstones hand-carved into artistic, cultural, or decorative designs with fine craftsmanship.

  • Strung Beads

    Beads strung on thread or wire.

Testing & Classification

All testing is carried out by following the pre-determined criteria strictly, although the tests to be performed largely depend on the form in which the gemstone is submitted for identification.

JGL classifies gems and minerals based on their group, species and variety, wherever applicable.

Hallmarking & Metal Testing

For Hallmarking reports all jewellery are tested using X-ray fluorescence spectrometers (XRF) as per well-established international criteria.

Disclosure of Enhancements & Treatments

Enhancements and treatments are routinely disclosed at no additional charge, subject to their identification using the analytical techniques available at JGL Delhi and the significance of such disclosure.

Reported treatments may include:

  • Coating
  • Foiling
  • Diffusion
  • Laser treatment
  • Coloured impregnation
  • Heat treatment
  • Fracture filling (including nature and quantification of filler in emeralds)
  • Irradiation and heating in diamonds
  • Various treatments in corundum (including heat, diffusion, fillers, etc.)

All identified treatments are clearly mentioned in the JGL Identification Reports.