The question of how many different minerals exist does not have a single, fixed answer, but reflects a dynamic process within the earth sciences. The total number is a reflection of Earth’s complex geological history and the strict definitions scientists use to categorize natural materials. This figure changes constantly as researchers discover new compounds in rare environments and as existing substances are re-examined under modern standards. The sheer number of known minerals highlights the vast diversity in chemical compositions and atomic structures that result from geological forces across the planet and beyond.
The Official Count and Tracking Body
The official tally of recognized minerals is maintained by the International Mineralogical Association (IMA), specifically its Commission on New Minerals, Nomenclature and Classification (CNMNC). This international body is responsible for establishing a consistent and universally accepted system for mineral species. The most current figures show that the number of officially approved mineral species is well over 6,000, with official lists continually being updated.
The CNMNC evaluates proposals from scientists worldwide, validating discoveries and standardizing the name and chemical formula for each new species. This centralized oversight ensures that every substance proposed as new is truly distinct from all others. The dynamic nature of Earth’s geology means that approximately 90 to 110 new minerals are officially approved each year, demonstrating that the inventory is perpetually expanding.
The Five Criteria Defining a Mineral
To be counted among the thousands of recognized species, a substance must satisfy a precise set of five criteria established by the scientific community. The first requirement is that a mineral must be naturally occurring, meaning it is formed by geological processes without human intervention.
This rule immediately excludes all synthetic gems and laboratory-grown materials, regardless of how closely they mimic natural counterparts. The second and third criteria specify that a substance must be an inorganic solid, which removes materials derived from living organisms, like coal or amber.
Coal, for example, is formed from ancient plant matter, which violates the requirement for an inorganic origin. Furthermore, the solid state requirement excludes substances like liquid water, though ice naturally occurring in glaciers does meet the definition of a mineral.
The final two criteria relate to the substance’s internal makeup, requiring a definite chemical composition and an ordered atomic structure. A definite chemical composition means the material can be represented by a specific chemical formula, even if minor substitutions of elements are allowed.
This rule excludes materials like the volcanic glass obsidian, which is considered a mineraloid because its composition varies too much and its internal structure is disorderly. The ordered atomic structure refers to a repeating, three-dimensional arrangement of atoms, ions, or molecules, known as a crystalline structure. Common window glass is not a mineral because its atoms are arranged randomly, making it an amorphous solid.
How New Minerals Are Discovered and Approved
The journey for a new mineral from initial discovery to official recognition is a rigorous, multi-step process overseen by the IMA-CNMNC. Discovery often occurs in geologically unique locations, such as remote volcanoes, deep-sea vents, or within meteorites, where extreme conditions create novel chemical combinations. Researchers isolate a tiny, often microscopic, sample of the suspected new material and begin an intensive laboratory analysis.
This laboratory work involves using advanced techniques like X-ray crystallography to map the substance’s internal atomic arrangement, which provides the evidence of a distinct structure. Detailed chemical analysis is also performed to determine the precise composition and formula, demonstrating that the material is not simply a variety of an already-known mineral.
Once the data is collected, the discoverers submit a formal proposal and checklist to the CNMNC, including the proposed name, which is often based on the locality, a characteristic, or a person. The commission’s international members then vote on the proposal, requiring a majority of over 75% for approval. Final approval grants the new species official status, but the discoverers are then required to publish a full, peer-reviewed description of the mineral, typically within two years.
Chemical Groupings of Minerals
Despite the large number of individual species, minerals are organized into a manageable number of chemical classes based on the dominant anion or anionic group in their composition. This classification system is effective because minerals sharing the same anion tend to exhibit similar characteristics and are often found in similar geological environments.
The largest and most significant group is the silicates, which account for over 90% of the Earth’s crust and are characterized by the silicon-oxygen tetrahedron building block. Carbonate minerals, which contain the carbonate ion (CO3), are another major group, including common rock-forming minerals like calcite.
Oxides are defined by a metal element bonded with oxygen, while sulfides contain sulfur bonded with a metal, but without oxygen. Finally, the native elements represent minerals composed of only one element, such as gold, silver, or carbon in the form of diamond or graphite.