Analysis of information sources in references of the Wikipedia article "Τανζανίτης" in Greek language version.
Tanzanite can sometimes be mistaken for blue sapphire, but tanzanite can have very pronounced pleochroism, which reflects different colors from different angles. Pleochroism is an optical phenomenon due to the double refraction of light which is divided into two "polarized" paths at a 90¡ angle to each other.
Companies such as TanzaniteOne Ltd. will be allowed to export rough gems larger than 5 carats in size, Peter Kafumu, the commissioner for minerals in the Ministry of Minerals and Energy, said in a telephone interview today from the commercial capital, Dar es Salaam.