Many Muslim scholars dealt with minerals and gems and wrote monographs on the subject. The golden age of their writings was the 4th-5th century after Hijra (AH) (10th-11th century AD).

They used almost all the physical properties known to us now to identify and differentiate minerals. Experimentation was a widespread habit in the study of minerals. Al-Biruni, in the author's view, was the leading scientist in this subject.

Mineralogy is the science of studying "minerals". A mineral is a naturally occurring substance that has a definite chemical composition and crystal structure. In other words, a mineral is a crystalline, chemical pure, natural material. Accordingly, gold, diamond, quartz, calcite, sapphire, pearl, … etc are examples of minerals. The importance of minerals and mineral resources are well known and do not need to be mentioned here.

Gems and precious stones are special types of minerals. They are rare, beautiful (in colour, transparency, lustre, … etc), and hard enough to resist physical and chemical changes for some time. Diamond, ruby, sapphire, emerald, … etc have these properties; they are gems and, of course, minerals. The importance of gems to emperors, kings and wealthy women was possibly the driving force behind their recognition since the dawn of human civilization.

The Ancient Egyptians, Mesopotamian people, Ancient Indians, Greeks, and Romans knew certain varieties of mineral, precious stones, and gems. Most of the lands of these people became part of the Islamic State "Caliphate". Consequently, their writings on gems and minerals, as was the case with other subjects, were translated into Arabic in the first 3 centuries A.H. Thus, it is not surprising to find the best contributions by Muslim scientists to mineralogy and gemmology in the 4th and 5th centuries A.H.

Scientists of the Subject

Most of what was written in the subject of minerals, stones, and gems was lost. A few monographs survived, and are now printed. In addition, information on the subject can be found in some encyclopaedic works. Here are some examples:

• Yahya Bin Masawaih (died 242 AH/857 AD), Gems and their properties.
• Al-Kindi, Ya'koub Bin Ishaaq (260AH/873AD) wrote three monographs, the best of which is "Gems and the Likes". It was cited by other writers in the subject. However, it was lost.
• Al-Hamdani, Al-Hasan Bin Ahmad (334AH) wrote three books on Arabia in parts of which he described methods of exploration for gold, silver, and other minerals and gems, their properties and locations.
• Ikhwaan As-Safa (2nd half of the 4th century AH) wrote an encyclopaedic work, which included a part on minerals, especially classification.
• Al-Biruni, Abu Ar-Rayhan Mohammad Bin Ahmad (440AH/1048AD) is in the authors view the leading mineralogist throughout the Islamic history. His monograph "Treatises on how to recognize gems"(Al-Jamhir fi Ma'rifatil Al-Jawahir) is probably the best contribution on mineralogy in the Muslim civilization. Throughout this manuscript, Al-Beruni did not translate or copy the science of other civilizations. Instead, he recorded his own experience.
• Al-Tifashi, Ahmad Bin Yousef (683AH), "Flowering Ideas on Gemstones"(Azhar Al-Afkar fi Jawahir Al-Ahjar) Although it is more than 200 years after the work of Al-Beruni, it is of lower scientific value. However, it is much superior both in classifying minerals and in the method of studying them, which is very close to what we see now in modern mineralogy books.
• Ibn Al-Akfani, Mohammad Bin Ibrahim (749AH/1348AD), "Special Treasures on Characteristics of Gemstones" (Nukhab Al-Thakhair fi Ahwaal Al-Jawahir). This monograph is scientifically of lesser quality than that of Al-Tifashi.

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