A Guide to Mineral Names and Classification Systems

Where Do Mineral Names Come From?

In most cases, a mineral is named after one of its physical properties, the locality where it was first discovered, or in honor of a scientist or other personage. Many minerals with a long history of use also have names derived from the Greek and Latin languages. 

Physical Properties

The following are some examples of minerals named after their chemical composition, morphology, or typical color.

• Arsenopyrite: so named because it consists of up to 46% arsenic (As) (with the mineral formula FeAsS).
• Axinite: from the Greek axine for "ax," alluding to the sharp crystals this mineral forms.
• Fibroferrite: from the Latin fibra for "fiber" and ferrum for "iron."
• Staurolite: from the Greek stauros for "cross" and lithos for "stone," alluding to the cross-shaped twinned crystals this mineral commonly forms. 
• Tetrahedrite: so named because of its tetrahedral crystal form.
• Rhodonite: from the Greek rhodos for "rosy," alluding to the mineral's pink or rose-red color.
• Albite: from the Latin albus for "pure white."
• Purpurite: from the Latin purpura for "purple."

Localities

Some minerals are named after their type localities, the sources that produced the specimens used to define the species. For example:

• Benitoite, a rare blue mineral, was named after the San Benito Mountains in California.
• Labradorite, a calcium-enriched feldspar mineral, was first identified through specimens from Labrador, Canada.
• Vesuvianite is named after Mount Vesuvius in Italy.

The discoveries of the specimens used to define the preceding minerals were well-documented. In contrast, some minerals were named after sources with popular but mistaken associations.

During the European Middle Ages, turquoise, "the Turkish stone," was so named because many Europeans believed the stone came from what is now Turkey. Although most turquoise entering Europe at that time passed through Turkey, Iran was most likely the source.

Amazonite is a more recent example of a mineral named after a mistaken locality. The noted mineralogist August Breithaupt officially named the mineral in 1847 after an unspecified type locality "near" the Amazon River. However, to date, there are no known sources of amazonite within the Amazon rainforest itself or near that famous river.

Scientists and Other Beings

Many minerals are named in honor of prominent scientists, such as:

• Breithauptite was named after the aforementioned August Breithaupt.
• Kunzite (a variety of spodumene) was named after the well-known American mineralogist George Frederick Kunz.
• Haüyne was named after the crystallographer René Just Haüy.
• Fluor-liddicoatite was named after the gemologist Richard T. Liddicoat, a luminary of the Gemological Institute of America (and also the presence of the element fluorine).

Some notable figures have even had several minerals named after them. Sklodowskite and cuprosklodowskite, both uranium-bearing minerals, were named after two-time Nobel prize winner Maria Skłodowska-Curie (Marie Curie), who conducted pioneering work on radioactivity.  Bixbite (red beryl) and bixbyite were named after the American miner and mineralogist Maynard Bixby.

Some minerals have even been named after mythological beings. For example, neptunite was named after Neptune, the Roman god of the sea. This was likely a humorous nod to the fact that neptunite was first discovered in close association with the mineral aegirine. As it turned out, aegirine was named after Àgir, the Norse god of the sea.

What Practical Information Can You Get from Mineral Names?

Specific prefixes and suffixes in mineral names can also indicate important information. Knowing what these prefixes and suffixes mean can help you understand the characteristics of some minerals based solely on their names.

Prefixes

Prefixes in mineral names can indicate crystallographic information. For example:

• "Clino-" indicates the monoclinic crystal system (e.g., clinomimetite, clinoenstatite).
• "Ortho-" indicates the orthorhombic crystal system (e.g., orthoserpierite).
• "Para-" indicates dimorphs, minerals with the same chemical composition but different crystalline structures (e.g., parahopeite).

Prefixes can also indicate determinant chemical elements. For example:

• "Hydroxy-" indicates OH-bearing minerals (e.g., hydroxylapatite, hydroxylellestadite).
• "Chlor-" indicates Cl-bearing minerals (e.g., chlorapatite, chlorellestadite).
• "Fluor-" indicates F-bearing minerals (e.g., fluorapatite, fluorellestadite).
• "Ferro-" indicates Fe-bearing minerals (e.g., ferroaxinite, ferrocolumbite, ferrotantalite).
• "Magnesio-" indicates Mg-bearing minerals (e.g., magnesioaxinite, magnesiocolumbite, magnesiotantalite).
• "Mangan-" indicates Mn-bearing minerals (e.g., manganaxinite, manganocolumbite, manganotantalite).

Suffixes

Suffixes can also indicate additional information about the mineral. Chemical suffixes commonly denote rare-earth minerals, such as monazite-(Ce), monazite-(La), monazite-(Nd), and monazite-(Sm). The suffix indicates the dominant rare-earth element in the mineral, such as cerium (Ce), lanthanum (La), neodymium (Nd), and samarium (Sm).

Guidelines for Prefixes and Suffixes in Mineral Names

Consult the following works for formal guidelines for using prefixes and suffixes in mineralogical nomenclature.

• Burke, E. A. (2008). "The use of suffixes in mineral names." Elements, 4(2), 96-96.
• Burke, E. A. (2008). "Tidying up mineral names: an IMA-CNMNC scheme for suffixes, hyphens and diacritical marks." The Mineralogical Record, 39(2), 131. (Accessed 10/19/24)
• Hatert, F., Mills, S. J., Pasero, M., & Williams, P. A. (2013). "CNMNC guidelines for the use of suffixes and prefixes in mineral nomenclature, and for the preservation of historical names." European Journal of Mineralogy, 25(1), 113-115.
• Rabinowitz, H., & Vogel, S. (2009). "Style and Usage in Earth Science and Environmental Science." The Manual of Scientific Style, Academic Press/Elsevier: Amsterdam, The Netherlands, 427-468. (Accessed 10/19/24)

How are Minerals Classified?

Minerals are classified mainly based on their chemical and/or crystal-chemical composition. The three most widely used classification systems are Nickel-Strunz, Dana's New Mineralogy, and A Systematic Classification of Minerals by James A. Ferraiolo. These systems have several editions and evolve constantly. 

The Nickel-Strunz Classification System

The Nickel-Strunz classification system uses numerical codes that reflect the mineral's chemical composition and crystal structure. Groups are organized based on the dominant anion in the mineral's chemical composition. Subgroups are organized based on the mineral's crystal structure. 

The Nickel-Strunz system divides minerals into ten classes:

• 01 Native Elements
• 02 Sulfides and Sulfosalts
• 03 Halides
• 04 Oxides, Hydroxides, and Arsenites
• 05 Carbonates and Nitrates
• 06 Borates
• 07 Sulfates, Chromates, Molybdates, and Tungstates
• 08 Phosphates, Arsenates, and Vanadates
• 09 Silicates
• 10 Organic Compounds

The Nickel-Strunz code scheme looks like this: NN.XY.##x, where:

• NN: mineral class number (from 01 to 10)
• X: Nickel-Strunz mineral division letter
• Y: Nickel-Strunz mineral family letter
• ##x: Nickel-Strunz mineral/group number; x is an add-on letter, if needed

Please note: the division and family letters are not the first letters or abbreviations of mineral names or the chemical symbol of cations. The Nickel-Strunz system assigns these letters to these subdivisions.

For example, the mineral corundum (Al₂O₃) has the following Nickel-Strunz code: 04.CB.05.

• "04" indicates that corundum belongs to the Oxides and Hydroxides group.
• "CB" indicates that it belongs to the medium-sized cations group.
• "05" represents a specific mineral species within this subgroup.

For more information on the Nickel-Strunz classification system, please visit https://www.webmineral.com/strunz.shtml.

Dana's New Mineralogy

The new Dana classification system also categorizes minerals based on their physical properties and crystal structures. However, codes in the Dana system consist of numbers only.

For example, corundum in the Dana system has the following code: 04.03.01.01.

• "04" stands for Oxide Minerals.
• "03" stands for simple Oxides with a cation charge of 3+. In the case of corundum, Al³⁺.
• "01.01" stands for the Corundum-Hematite group with a rhombohedral crystal system.

Consult Dana's New Mineralogy for more information on this classification system.

Who Determines Valid Mineral Names?

As of November 2024, the International Mineralogical Association (IMA) officially recognizes 6,100 valid mineral species. The International Mineralogical Association Commission on New Minerals, Nomenclature, and Classification (IMA-CNMNC) regulates mineral names, including naming newly discovered species and announcing discredited species. The IMA's official list of approved mineral names provides a centralized reference for the scientific community. You can consult the most recent list to confirm the status of any mineral name. (There is a link to the list on the IMA website).

The IMA has also published A Compendium of IMA-Approved Mineral Nomenclature, a set of guidelines for the systematic naming and classification of minerals.

What is a Mineral Variety?

Mineral species may have varieties distinguished by colors and optical phenomenal effects. For example, rubies and sapphires are varieties of the mineral corundum — an IMA-approved species. Red corundum is considered ruby, while all other colors of corundum are sapphire. Star sapphires and star rubies are also considered varieties of corundum. These varieties display asterism, the "star stone" effect. Despite these variations, rubies and sapphires, with and without asterism, all have the same chemical formula and crystal structure. They are all corundum.

The cause of color variations and phenomenal effects may result from trace elements or inclusions of other minerals within a mineral. For example, emerald is the green chromium (Cr)-bearing variety of the beryl mineral species, Be₃Al₂Si₆O₁₈. Bear in mind that the presence of chromium in emerald doesn't make it a species distinct from beryl. In emerald, chromium is a trace element, not an essential element. It's not a part of the beryl formula and doesn't influence crystal structure. Nevertheless, its presence does produce a green color in beryl.

Other trace elements can also cause green color in beryls. Vanadium (Vr) can produce an emerald-green color in beryls.

Are Mineral Variety Names Regulated?

The IMA list only includes official mineral species names, but many more names are attached to mineral varieties. However, mineral variety names remain unregulated. The IMA only regulates mineral species names.

Differences of opinion over mineral variety names do occur, especially within the gem trade. Emerald is one example. Some gemologists would classify green Vr-bearing beryls as emeralds along with green Cr-bearing beryls. Some gemologists may restrict emeralds to beryls with a particular shade of green, regardless of the trace element. Despite these differences of opinion, emerald remains a variety of beryl and not a separate mineral species. Gemologists have also argued over the exact definition of "red" when distinguishing rubies from pink sapphires. However, these disputes lie outside the domain of mineralogy.

Do Mineral Names Have Synonyms?

Some IMA-approved mineral species may have synonyms or alternative names. (Mineral varieties themselves can also have their own synonyms). Please note that the IMA does not regulate synonyms, even if the mineral species has an official name.

Synonyms can also be subdivided into the following:

• Chemical name synonyms
• Commercial synonyms
• Common synonyms
• Obsolete, antiquated, or historical names
• Language (foreign) synonyms
• Regional names
• Alternative spellings
• Misleading names

Here are some examples:

• "Asteriated" is an antiquated term for stones that show asterism. Thus, "asteriated sapphire" is a synonym for star sapphire.
• Padparadscha is a variety name for corundum with pinkish orange "lotus color." However, you may find the Sinhalese name padmaraga used instead. Sinhalese or Sinhala is one of the principal languages of Sri Lanka, a major source of these sapphires.
• "Balas ruby" is a historical — and now misleading — name for red spinels.

Mineralogists should use official names for mineral species in their communications to avoid possible confusion. Of course, the popular use of mineral variety names and synonyms will continue.

For a detailed classification of mineral varieties and synonyms with numerous examples, consult "Classifying minerals and their related names in a relational database," a 2023 paper by Gavryliv et al..

Olena Rybnikova, PhD

Olena Rybnikova is a gemologist and mineralogist. She has a PhD in mineralogy and petrology specializing in beryllium minerals and is a certified Applied Jewelry Professional accredited by the Gemological Institute of America. Her passion is actively promoting knowledge and appreciation of nature, geology, and gemstones.

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