Testing the Colour of Gemstones - A Collection of Historical Articles on the Dichroscope, Filters, Lenses and Other Aspects of Gem Testing - Bog af Va

Testing the Colour of Gemstones - A Collection of Historical Articles on the Dichroscope, Filters, Lenses and Other Aspects of Gem Testing - Various

Testing the Colour of Gemstones - A Collection of Historical Articles on the Dichroscope, Filters, Lenses and Other Aspects of Gem Testing - Various