Abstract

The Book of the jamahir  in Knowing Gems occupied the center stage despite the dozens of books that were written in stones and minerals before and after him, as his book is considered the most important in the sciences of minerals, gems and metals, and it is one of the first among their meanings and placed the specific weight of some metals and gemstones and mentioned that many of these gems are similar in color.  But it is not different in nature.
 Al-Biruni devotes in his work a chapter to each type of minerals, gems and gemstones, and from these chapters the separation of pearls as this chapter began with a discussion of the atemology of pearls and their description by linguists, and follows them by describing the characteristics of the types of pearls, their location and analysis of their physical properties.  Then he mentions its titles among the essentials, and after that he discusses its value and price in the market, taking into consideration the different degrees of purity and optical properties of it, then he follows it with methods of repairing what has spoiled pearls, then he comes to mention the sea and the yam and follows it by mentioning the shells, the places of pearls and the cesspits and their depths, the times  and the way of wicker, and this is what he touched  To him, after presenting an overview of Al-Biruni and his book Al-Jamahir in Knowing the Gems, in terms of the meaning of the author's name, when he wrote it, the most important reasons that led him to write it, the most important sources on which he relied  in his work, and what is the methodology that Al-Biruni followed in his book.