From the historical point of view, the mineralogical collection is the main collection of the department, consisting of over 100,000 recorded specimens of minerals, representing over 1,750 mineral types.
The mineralogical collection is one of the National Museum's oldest collections. Its core was formed at the time of the museum’s foundation by merging several private collections of minerals donated by noble patrons, headed by Count Kaspar Maria von Sternberg. From the historical point of view and with regard to the number of items and specimens, the mineralogical collection is the main collection of the department of minerology and petrology. Over the 200 years of its existence, the collection has expanded from the initial 8,500 pieces to over 100,000 catalogued items.
The mineralogical collection includes specimens of minerals originating in the second half of the 18th century (some possibly from the 17th century), as well as new finds from the Czech Republic and worldwide. From its very beginnings to the present day, the collection has been shaped to represent a complete overview of the mineral resources of the Czech state, and at the same time to include comparative samples of minerals from foreign deposits, and to contain the greatest possible number of known types of minerals and varieties according to the international mineralogical system. The mineralogical collection has thus become a unique archive of natural materials, documenting the often-varied mineralogical situation in today's mostly inaccessible former mines and other natural sites.
The mineralogical collection is not limited to the rich representation of specimens of aesthetic value, of excellent shape and brilliant colour, but also brings together specimens of high documentary and scientific value (including dozens of holotypes of new minerals) regardless of their beauty and distinction.
Nowadays, the mineralogical collection contains almost 1,750 types of minerals (from the known total of 6,000) of various shape and colour and paragenetic sequence, differing in their genesis and place of origin, whether domestic or foreign. Some rare minerals are represented by only a few specimens; others, more abundant, by hundreds or thousands. The size of the mineralogical specimens is varied, too – from microscopic grains in polished samples for microscopic examination, through crystals several millimetres in width (alluvia, for example) or decimetres wide, to over one-meter-wide druses of crystals of quartz, calcite, fluorite, galena and other minerals.
In addition to cataloguing new additions, the increased documentary value of the mineralogical collection derives from the detailed revision of collection items using laboratory methods (the revision of some collection items, including the determination of new types for individual locations and for the worldwide mineralogical system), the digitalization of collection items and finally the solution of the provenience of collection items with incomplete or erroneously identified locations.