The mineral diversity of Bulgaria is fully presented with complete collections of important mineralogical sites, a big part of which are already exhausted deposits or destroyed fragments of the mineral nature.

Regional collections from more than 900 localities are stored here. They represent 37% of the 800 mineral species found in Bulgaria and this is the biggest collection of preserved Bulgarian minerals. An important part of them are holotypes of new minerals found in Bulgaria: strashimirite from Zapachitsa, balkanite from Sedmochislenitsi, vasilite from Novoseltsi, orpheite from Madzharovo, manganilvaite from Mogilata, as well as originals of cited in literature rare minerals, such as agardite from Ossenovlak, mckinstryite and stromeyerite from Sedmochislenitsi, sperilite from Blagoevgard region, ruderfordite from Iskrets, osarizawaite from Chala, maskanite, tschermigite, millosevichite, godovikovite from Pirin mine near Brezhani.

The permanent exhibition of this department mirrors the mineral diversity of Bulgaria and presents the most attractive and the most valuable mineral samples grouped under the following themes:

Minerals from Kremikovtsi deposit – the recently found mineral Segnitite, a unique coarse crystalline norsethite, witherite, rodochrosite, spearlike and platy crystals of barite, hematite, goethite, lepidocrocite, malachite.

Mineral diversity of pegmatites from Ardino area, one of the few places in Bulgaria, where one can find gemstones: aquamarine, morganite, heliodor, garnet.

Mangano calcite from the hottest mine in Bulgaria (56o C), Erma reka? Androvo?, Zlatograd – crystal druses with deep pink colour crystals in various shapes.

Mineral diversity of Vitosha Mountain – molibdenite and titanite, double terminated monocrystals of dravite and tourmaline suns, cut and polished decorative stones from Prof. Angel Angelov’s collection.

Gipsum from Troyanovo 3 mine, Radnevo – crystals and twins with various morphology.

Agates from Bulgaria – a rich collection of various in colour and pattern agates from the Eastern Rhodopes and Shumen region.