Ted working with LIBS in the UK

26 samples for LIBS testing mounted on a "blue-tak" ready for firing. A beryllium washer mounted on the upper left size of the firing platform, serves as the comparator with known beryllium concentration.

Spectrogram of a Be-treated sapphire shown the Be peak at ~313 nm. Note the damage of the specimen caused by the laser ablation.

Ocean Optics model LIBS 2000+ setup selling for about US$48,000 in 2004

Sample #19 broke into 3 pieces caused by a
200 mJ laser pulse at f=10mm using Ocean
Optics's 2000+ LIBS setup. Sample damage
is the biggest and most serious problem using
the LIBS method.

LIBS ( LASER INDUCED BREAKDOWN SPECTROSCOPY)
On January 10, 2005, a batch of 20 gems was tested for beryllium by the scientist involved in the development of the ocean Optics' LIBS-2000+ system. Test results: 17 out of the 20 samples were identified correctly, 3 samples failed the test including one sample where beryllium was detected at 234nm (instead of the 313nm). One sample broke into 3 pieces. That's about 15%-20% error tolerance which matches the error tolerance of my previous LIBS tests performed at the Applied Photonics (Skipton, UK) LIBS lab.The results of the new tests are also in direct contradiction with the conclusions made by SSEF headed by Dr. Hanni et al, the marketers of LIBS, who are avoiding the "error tolerance" issue on the Be-treated corundums and misleading the gemological community.

On a related article "A New Method for Detecting Be-DiffusionTreated Sapphires: LIBS" by Dr.Hanni et al, published in the G&G Winter 2004 issue, the authors never recognized or gave any reference to my pioneer work published in the Australian Gemmologist (Vol. 22, Number 4, Oct.-Dec. 2004) "LIBS: A Spark of Inspiration in Gemmological Instrumentation" which marked the first published account on the subject. Dr.Hanni et al have declared war on my work exercising pressure to trade organizations and to the members of the gemmological community trying to discredit my work. The industry should remember that the LIBS METHOD TESTING FOR BERYLLIUM IN CORUNDUM IS STRONGLY INDICATIVE, NOT CONCLUSIVE.

By 2007, the AGTA gem testing lab dramatically reduced the use of the LIBS method in testing for beryllium, since conclusive results cannot be always obtained. Other commercial gemlabs have abandoned the LIBS method and bought LA-ICP-MS equipment. For one more time I was correct in my work, which was largely ignored by the commercial labs. More bitter juice is expected from the labs but they do not talk about it.

GEMOLOGICAL APPLICATIONS OF LIBS: Examination of stones tested with LIBS by Applied Photonics and Ocean Optics are provided in my heat-treatment training course

PURCHASING LIBS EQUIPMENT: LIBS configurations are readily available on the market for as low as US$48,000. Click http://www.oceanoptics.com for more information and pricing. Special LIBS equipment for detecting only beryllium in corundum may be assembled by knowledgeable individuals using OEM parts. Special attention should be given to the type of laser used and a new "targeting" methods should be devised. The cost ranges from US$25,000 to US$30,000 for a certain protion of the spectrum where the 313nm resides. Since 2005, the SSEF commercial gemological laboratory headed by Dr.Hanni was selling a modified LIBS for about US$80,000. At Ted's opinion the LIBS is not recommended for general gemological use, except in few isolated cases. However, future buyers should attend LIBS conferences and trade shows to meet the real LIBS experts.

LIBS CONFERENCE: Read the proceedings of the LIBS-2004 Conference (Sept. 29 to Oct.1 2004) in Malaga, Spain. Click http://www.uma.es/libs to read more on the subject. Next LIBS conference: Sept. 2005 in Aachen (Germany). Check the Internet for LIBS regional trade shows and seminars.

MORE on LIBS: A paper on LIBS and its applications in gemology was presented by Ted Themelis at the International Gemmological Conference in Wuhan,China, Sept 12-18 2004 and published in the IGC proceedings.