Mineralogy

Mineralogy is the scientific discipline concerned with the study of natural elements and compounds that constitute the solid portions of the universe. This field focuses on the chemical, physical, and structural properties of minerals as well as their origins, classifications, and economic applications. Throughout history, mineralogy has developed in parallel with chemistry, physics, crystallography, and earth sciences.

Natural Mineral Samples (AA)

Historical Development

Due to the broad significance and diverse applications of minerals, the science of mineralogy has evolved simultaneously with many other disciplines including chemistry, physics, crystallography, and earth sciences over more than two millennia. Mineralogical research has consistently focused on four fundamental questions:

1. What is the origin of minerals?
2. What are their characteristic chemical, physical, and structural properties?
3. How should they be classified?
4. What are their economic applications?

The history of mineralogy saw a transformation from a qualitative discipline to a quantitative science during the 18th and 19th centuries, driven by advances in chemistry and physics.

Ancient and Medieval Theories

The earliest knowledge about minerals was typically found in alchemical, cosmological, and philosophical texts. In antiquity and the Middle Ages, minerals were grouped together with other inanimate natural objects such as fossils, rocks, and soils.

The earliest theories were based on observations of mineral growth. The observation that cave formations, salt deposits from seawater evaporation, and even kidney stones appeared to grow provided clues about the origins of other minerals. Since all these processes involved liquids, pre-18th century theories generally invoked the concept of “lapidifying juices”—substances that solidified under the influence of heat or cold.

The earliest explanations of minerals can be traced to mythological accounts in Egyptian and Indian civilizations. In the 3rd century BCE, Zosimus proposed an influential theory regarding the origin of metals. According to this theory, known as transmutation, all metals fundamentally consist of two primary elements: sulfur and mercury. It was believed that different combinations of these two elements under varying pressure and temperature conditions produced various metals. This view significantly influenced the development of alchemical practices that sought to transform one metal into another, especially into gold.

Mineralogy in Islamic Civilization

Scholars of Islamic civilization inherited the Greek heritage in mineralogy and conducted original research that became foundational reference sources in the West until the 16th century. The primary sources for Muslim scholars were Dioscorides’ Materia Medica and Galen’s Peri kraseos kai dynameos ton haplon pharmakon. However, the first systematic work on mineralogy in Islamic scientific history was Kitâbu’l-Ahcâr (Book of Stones). Long attributed to Aristotle, the original Greek text of this work is lost; only its Arabic translation survives. This work contains information on approximately 700 types of stones and their properties and influenced both Islamic and Western literature—for example, the 15th-century Tuhfe-i Murâdî and William Gilbert’s De Magnete.

Natural Mineral Samples (AA)

Geology and Mineral Formation

Unlike Arabic pharmacological texts, cosmological and natural philosophical writings in Arabic devoted greater attention to the formation of minerals and geological processes.

In the 10th century, İhvân es-Safâ classified minerals into three groups according to their formation time: rapidly formed (such as dust, clay, and salt), slowly formed (such as coral and pearls from marine organisms), and very slowly formed (such as metals and precious stones). They also explained geological processes linked to a 36,000-year precession cycle and proposed that mountains are reformed through erosion and sedimentation.

Ibn Sina devoted significant attention to mineralogy and geology in his work Kitāb eş-Şifāʾ. This section, translated into Latin as De congelatione et conglutinatione lapidum, was long believed in Europe to be authored by Aristotle.

Ibn Sina rejected the alchemical theory of “metal transmutation.” He argued that each metal possesses its own unique temperament and that alchemists’ efforts were merely superficial imitations. He proposed two ways in which stones form: through the drying and hardening of mud or the condensation and solidification of water. He noted observing a clay deposit on the banks of the Amu Darya River transform into stone over 23 years. He explained mountain formation through erosion and accumulation processes and cited marine shells found on mountain peaks as evidence for this view.

Physical Properties and Classification

Arab scholars meticulously examined the physical properties of minerals, including hardness, weight, color, luster, transparency, taste, and odor.

Al-Biruni (d. 1048), in his work Kitâbu’l-Cemâhir fî Ma‘rifeti’l-Cevâhir, examined 31 stones according to their physical characteristics and locations. He determined that the hardness of ruby follows that of diamond, aligning with the Mohs hardness scale developed in the 19th century. Al-Biruni also used a conical measuring device he developed (a picnometer) to determine the densities of metals such as gold, mercury, copper, and iron with values remarkably close to modern measurements.

Ibn Sina classified minerals into four groups: stones (aḥcār), fusible substances (metals), sulfurs (combustible substances), and salts (water-soluble substances). This classification was later adopted by European scholars such as Albertus Magnus.

Abu Bakr al-Razi (Kitâb el-Esrâr) systematically classified stones and salts; Ahmad al-Tifashi (Ezhâr el-Efkâr fî Cevâhir el-Aḥcâr) examined minerals according to their formation, occurrence, properties, powers, and commercial value, providing detailed information on emerald mining in Egypt.

Cevhernâmeler (Books of Gems)

In the Islamic world, mineralogy contributed to the emergence of a distinct literary and scientific genre known as cevhernâme. These works described the physical properties, benefits, harms, and attributed powers of stones. The earliest known Turkish cevhernâme is Tuhfe-i Murâdî, written during the reign of Murad II in the 15th century by Muhammad ibn Mahmud al-Shirvani. This work is largely based on al-Tifashi’s Ezhârü’l-Efkâr. Precious stones such as agate, ruby, coral, and pearl became central metaphors for beloved figures in classical Turkish poetry.

Modern Mineralogy and Scientific Transformation

Advances in chemistry and physics during the 18th and 19th centuries transformed mineralogy into a quantitative science. Robert Boyle established the modern definition of an element, and Jöns Jacob Berzelius developed chemical analysis methods. Eilhard Mitscherlich introduced the concepts of isomorphism and polymorphism, laying new foundations for classification. Abraham Gottlob Werner’s system based on external characteristics and his student Friedrich Mohs’s ten-point hardness scale remain in use today.

In crystallography, Niels Stensen described the angles between crystal faces, and René-Just Haüy explained the mathematical principles underlying crystal forms. In the 19th century, Christian Samuel Weiss, Auguste Bravais, and J.F.C. Hessel defined crystal systems and point groups; Fyodorov, Schoenflies, and Barlow identified the 230 space groups. In 1912, Max von Laue’s discovery of X-ray diffraction enabled the Bragg family to determine the first mineral structures, marking the beginning of modern crystallography.

Modern Classification

In the 19th century, two approaches to mineral classification emerged: Werner’s “natural history” system based on chemical composition and external characteristics, and Haüy’s method based on crystal form. The currently accepted system is the crystallochemical approach developed by James Dwight Dana in 1850. This system classifies minerals according to their chemical composition (elements, halides, sulfites, silicates, etc.) and crystal structure.