A 16th century trading book as a source of mineralogical knowledge

A trading book of the 16th century was analyzed as a separate source with a view of exploring the nature of mineralogical knowledge that our ancestors living in the 16th–17th centuries had. The analysis included comparison of the stones mentioned in the book with genuine minerals including review of the listed mineralogical characteristics. The paper notes that the book describes primarily true mineralogical properties in contrast to books of home remedies and books of herbal cures as well as books of official and prohibited booklore. The main method to distinguish between the most precious stones and less valuable ones is based on analysis of stone hardness. This mineral property is still widely used for their diagnostics based on the Mohs scale of mineral hardness, with scale number from 1 to 10. The author of the trading book suggests to use special “standards” for determining the most precious minerals such as fragments of true gemstones (jachont, lal, and emerald). It is rather important that he mentions emery as material for processing precious stones. Along with the finds of unprocessed gemstones in the layers of the 16th–17th centuries it is an evidence of existence of jewelry workshops.