International gem testing laboratory Jaipur

International Gem Testing Laboratory.
Jaipur.

Interesting gemology classs

Today shreelankan person come. To visit our lab and give us a brief knowledge of gems heating in shree lanka

Laser ablation analysis: know your lab!
More and more gem testing laboratories are applying Laser-Ablation ICPMS (LA-ICPMS) analysis to determine the trace element pattern of gemstones to meet the requirements of the industry. At the Gübelin Gem Lab, we have started to use this method on client stones more than eleven years ago, continuously expanding our knowledge, and permanently investing into the most cutting edge equipment. This allowed us to get a maximum of reliable data with a minimum impact on the stone. LA-ICPMS analysis applied by the Gübelin Gem Lab creates no more than three pits on the girdle, not exceeding 50 micrometres ( = 0.05 millimetres) in diameter and about 30 micrometres in depth. These pits are invisible for bare eyes and do not cause any measurable weight loss. However, we come across gemstones with significantly larger and also more numerous pits, sometimes even placed on facets. The picture above shows our small pit in the centre, and two much larger pics made by another lab. To avoid any bad surprises, we encourage dealers and jewellers to get in touch with their gem labs, and ask for the number and the maximum diameter of the laser pits, and the possible location on the stone.

Do gem labs rely on machines only? The answer here is: Not exclusively, but more and more machines support humans for the following reason: they tend to work in a more reproducible way, and are not susceptible to human errors and biases. Machine work is less prone to external influences. But obviously, to rely on machines alone would not be wise. The Gübelin Gem Lab strives for the perfect combination of human skills and technology. Certain tasks require traits that machines cannot (yet) provide. It is the combination of standardized data gathering (predominantly by machine, where a high quality of data can be reached), the automated evaluation (fully or supported by software) and the ultimate plausibility check (by human experts) that yields the optimum level of consistency and trueness.

The determination of the presence or absence of clarity enhancement in comprises two questions: Firstly, is there any foreign material in surface-reaching fissures? And secondly, is this foreign material having a clarity enhancing effect on the stone, i.e. is the visual appearance improved due to this material in the fissures? Only when both conditions are met, the stone is considered as clarity enhanced. Hence, diamond powder, dried-out oil, or any other material that is considered having no enhancing effect on the clarity, or that worsens the clarity, is not considered a clarity enhancement.

We recently found this large three-phase inclusion in a morganite. The three phases consist of a colourless liquid, a round, strongly reflective gas bubble and a solid mineral grown as a white, fibrous aggregate.