SEMINARIO DE INVESTIGACIÓN
Departamento de Investigación en Física
Universidad de Sonora
“On going studies of treated and non- treated corundum samples with ibil and
other complementary techniques”
Dr. Tomás Calderón
Universidad Autónoma de Madrid. Cantoblanco, Madrid, España.
“Traditional gemmology testing methods applied to differentiate between treated and non-treated specimens are more and more insufficient to spot out the state of the art procedures of enhancing gemstones. Such is the case of Corundum minerals (α-Al2O3: Ruby and Sapphire) where refractive index, specific gravity, pleochroism, absorption spectra or observation under UV light lead usually to no conclusive results when colour-diffusion processes are involved.
A different approach is thus required to solve this problem. Some techniques such as Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS) or Laser Induced Breakdown Spectroscopy (LIBS) have already been proposed as an alternative to the classic methods. Where SIMS detects treatment involving beryllium diffusion, XPS has been used to study in-homogeneities in certain types of Ruby”
Auditorio del Departamento de Física, Edif. 3F. 27 de Enero, 2010, 13:00 Hrs.