The Indian Gemmological Institute, now known as IIGJ-Research & Laboratories Center, Delhi, is a project of GJEPC, sponsored by the Ministry of Commerce & Industry, Govt. of India. Since its inception in 1978, 48 years ago, IIGJ-RLC (formerly IGI) Delhi has been rendering unbiased gemmological testing services to the general public as well as the gem & jewellery industry. IIGJ-RLC, Delhi also offers guidance to various government agencies and gemmological training institutions and shares R&D with the gem & jewellery industry and general public through write ups and articles for knowledge enhancement.
IIGJ-RLC, Delhi believes in quality service, and upgrades the lab with technological innovation adaptation on an ongoing basis.
Our planet is yet not wholly discovered. New deposits and new gemstones keep getting discovered. Not only in nature, but in trade also different kinds of synthetics and treatments also keeps developing along with new developments in technology. IIGJ-RLC, Delhi strives to keep up with detecting of such discoveries and inventions, so that lay persons can get possible disclosure about the gems they are investing in.
Along with the basic gemmological instruments like Microscope, Refractometer, Polariscope, Dicroscope, Spectroscope, U.V.Lamps, Chelsea Filter, etc., IIGJ-RLC, Delhi is well-equipped with advanced instruments like Diamond View, Fourier Transform Infrared Spectroscopy (FTIR), Ultra Violet-Visible-Near Infrared Spectroscopy (UV-VIS-NIR), Diamension and diamond screening equipment like Q.Check and Synthdetect.
Each report issued by IIGJ-RLC, Delhi is concluded on the basis of thorough expert analysis of stone/jewellery submitted for testing, as per the scientific tests performed with gemmological equipment. Both the identification and diagnosed treatment are mentioned on the report with the stone’s photograph.
Traditional Gemmological Methods
Traditional gemmological tools and methods play an important role in determining the nature of mineral species, which mainly involve determining the physical and optical constants and comparing with tables of their standards, available in common gemmological texts. These mainly provide qualitative information but still considered as important tools for gem identification. The most commonly tools used are polariscope, dichroscope, refractometer, spectroscope, UV lamp and specific gravity measurements
The microscope remains the most important tool in gem identification – it is the ‘heart’ of a gemmological lab. Detailed and careful observations made under a microscope help a gemmologist to decide on many aspects of a gem regarding its type, origin, treatments, etc and assists other techniques in validating the data. At the IIGJ-RLC, every analysis is started with a detailed microscopic observation.
Fourier Transform Infrared (FTIR) Spectrometer
Due to a typical crystal structure with specific pattern of molecular arrangement, particular gemstones or minerals tend to produce a characteristic absorption and transmission patterns on interaction with light. FTIR typically uses infra red light to study such features.
At IIGJ-RLC, FTIR is commonly used to identify unknown gems and minerals by their fingerprint pattern, separate natural and synthetic emeralds, rubies, sapphires, amethysts, etc, determine absence or presence of treatments in rubies, sapphires, emeralds, turquoise, corals, etc.
Laser Raman Spectrometer (LRS)
LRS is based on the Raman Effect, produced when a laser strikes a molecule and interacts with its bonds. Some of the light is scattered while some are re-emitted producing a characteristic spectra, which is a ‘fingerprint’ for a particular substance.
At IIGJ-RLC, Raman spectrometer is commonly used to identify an unknown gem material, or when stones are set in jewellery, such as black diamond and black moissanite, or to determine components of a rock; to detect treatments such as impregnation on turquoise or coral, low-temperature heating in rubies, HPHT in diamonds, etc; or to separate natural from synthetic diamonds
Ultra Violet-Visible - Near Infrared Spectrometer
UV-Vis-NIR spectrometry is based on selective filtering of wavelengths through the sample; the absorbed wavelengths caused due to electron defects or chromophoric elements are displayed in the form of a graph and expressed in comparison with the incident light.
At IIGJ-RLC, UV-Vis-NIR spectrometer is used to identify a gem species / variety, especially in case of separation of emerald from green beryl or ‘cuprian’ tourmaline from ‘non-cuprian’, or the type of garnet; it also helps to differentiate synthetic from natural sapphires or spinels, turquoise or corals their imitations, etc; it is also very useful in separating treated corals, jadeites, turquoise, diamonds, etc.
Energy Dispersive X-ray Flouroscene (EDXFR) Spectrometer
X-ray fluorescence spectrometry is used to determine the bulk chemical composition of the samples' surface. When a substance is exposed to x-rays, the electrons of the atoms get excited to the higher energy level and on falling back to the ground state, emit radiations in the form of fluorescence, which is recorded by the detectors. The emitted energy of excited elements is displayed as peaks.
EDXRF provides a quick chemical composition of a sample, thereby assisting in separating lookalikes, determination of type of glass-filling in rubies, coatings in tanzanite or diamond, separating turquoise or coral from imitations, etc
DiamondView basically is an imaging system, which uses the short-wave ultraviolet light below ~225 nm. The fluorescent reactions are observed through a CCD camera, which display them on the monitor through software. It helps in studying the growth pattern of the sample’s surface or sub-surface up to few microns. It also assists in observing 'phosphorescence' of a sample.
Although, DiamondView was created to study and separate synthetic from natural diamonds, it has proved to be quite useful for identifying treated and synthetic counterparts of rubies, sapphires, emeralds, etc.
Diamond Cut Scanner
The scanner basically measures dimensions of cut & polished diamond and gemstones, where it scans angles of inclination and position of each facet and measures each facet edge to create a 3D wireframe model. The software calculates exact proportions and symmetry of a cut diamond, thereby providing information on the performance of light within a cut diamond.
Whether it is a single gemstone or multiple gemstones of the same type, or various types of gemstones mounted in a single piece of jewellery, or a decorative item, IIGJ RLC’s jewellery reports cover all aspects in a single report. Our unbiased approach in mounted diamond grading makes our lab one to search for.
Diamond reports cover various aspects of a diamond from identification and separation of natural diamond from synthetic (lab-grown) or imitation diamond and detection of treatments, to determination of quality grades, whether mounted or loose.
IIGJ-RLC offers gemmological reports for majority of gemstones available in the market, based on vast gemmological experience of the gemmologists along with scientific facts drawn from various advanced spectrometers.