Little School of Mineralogy – 4
How were minerals classified in the past?
The earliest classification of minerals was based on their practical use, so minerals were divided into ores, gemstones, pigments and others.
The earliest classification based on external characteristics and some physical properties of minerals, such as colour, solubility, malleability and fracture, was introduced in the 8th century by the Arab physician, philosopher and alchemist Jabir ibn Hayyan, better known as Geber. It was later expanded and supplemented by Avicenna in the 10th century, Agricola in the 15th century and Werner in the 18th century.
The first chemical classification of minerals was proposed in the 18th century by the Swedish chemist and mineralogist Torbern Olof Bergmann, but his attempt was premature because many chemical elements had not yet been discovered at that time.
What is today’s mineral systematics based on?
Today’s mineral systematics is based on Berzelius’s chemical classification of minerals, which was further elaborated by the German mineralogist Karl Hugo Strunz.
While working as a curator at the Mineralogical Museum of Friedrich Wilhelm University, Strunz classified the museum’s mineralogical material based on crystal-chemical properties and thus introduced a chemical-structural classification of minerals.
According to this principle, minerals are divided into classes based on the dominant anion or anionic group.
Minerals that have the same dominant anion or anionic group often occur together in the same or similar geological environments and have many more similarities than minerals that contain the same dominant cation.
How are minerals classified?
In addition to Strunz’s system, mineralogy also uses the Dana classification system, which is likewise based on the chemical-structural characteristics of minerals.
All minerals discovered to date are classified according to this principle into 13 classes:
Class I – native elements
Class II – sulphides
Class III – sulphosalts
Class IV – oxides and hydroxides
Class V – halides
Class VI – carbonates
Class VII – nitrates
Class VIII – borates
Class IX – phosphates, arsenates, vanadates
Class X – sulphates
Class XI – tungstates, molybdates
Class XII – silicates
Class XIII – organic compounds
Prepared by Biserka Radanović-Gužvica