This article introduces the necessary steps in Identifying a Natural Untreated Sapphire
This page provides a list of RI, SG & Hardness of most gemstones.
This article by GIA is a very accurate description of the present situation in Ambatondrazaka, which is by far one of the most precious deposits of Sapphire we have ever seen.
Mambilla has been producing high quality Sapphires for many years now but the recent find is exceptionally interesting. GIA's expedition is the most complete document on this subject.
The Kataragama deposit in Sri Lanka sparked a massive Sapphire rush in Ceylon and this article provides a detailed study of this new mining zone.
The Montepuez deposit in Mozambique is the most significant source of Ruby both in terms of quality & quantity. This article by GIA provides a detailed study of the region.
This article by Swiss Gemological Institute clearly describes the present methods of heating by diffusion & fillings along with methods of identification.
This is one of the most interesting & creative articles of Gemology from our point of view. Solving the identification conundrum of low temperature heat treatment by studying radioactive Zircon inclusions in Sapphires is just breathtaking. Excellent Job SSEF!
Beryllium treatment has made many impossible colors a reality which makes its identification and understanding very important. This article by GIA is a very complete research on this subject.
