The Systematic Collection displays 4,500 samples of the over 10,000, belonging to the 9 classes of minerals, the presentation order within each class being the one established by the German mineralogist Strunz. There are illustrated over 700 distinct mineral species (approximately 850 denominations, including varieties), originating from Romania or abroad, of a very diverse spectrum and from significant geologic localizations (occurrences).
1.Native elements include the Native Gold Collection, the first native element. Other well represented native elements are copper, silver (for example, from Kongsberg, Norway), iron, arsenic (spheroid aggregates from Săcărâmb and Hondol, Romania, or from Echizen, Japan), sulfur (crystals of up to 6 cm from Girgenti, Sicily), graphite and diamond. Of great scientific value are the samples of tellurium, a rare mineral described for the first time in the world in Romania (Faţa Băii, near Zlatna, Alba county) by Müller von Reichenstein (1782).
2.Sulfides, sulfur salts, telluriums. This is one of the best illustrated classes of minerals in the Systematic Collection, given the abundance of minerals of this type in the deposits of Romania. In the majority of cases, this class groups minerals with a metallic aspect, of which traditionally there have been obtained the main metals for industrial purposes (Cu, Pb, Zn, etc.). The best known among these are chalcopyrite, sphalerite and galenite. There can be admired perfect pyrite crystals of up to 3.5 cm from the Bucium-Arama mine, Alba county (the dimensional "national record" registered by this mineral) as well as crystals of stibnite of various shapes, from the region of Baia Mare. A group of rare minerals of great scientific value is represented by the gold and silver tellurides from the West Carpathians: petzite, sylvanite, krennerite, nagyagite – described for the first time in Romania (Săcărâmb, Baia de Arieş), while hessite (Boteş) shows crystals of great dimensions (1-3 cm).
3.Halogenides. Approximately 12 million years ago, the Transylvanian Depression was a huge salt lagoon that, as a result of progressive evaporation, has covered itself with a massive layer of gem salt, a sedimentary rock consisting of the mineral halite. Thus, various halite crystals are part of this collection, reaching large dimensions (up to 13 cm), from diverse mines (salines) of this region as well as from other "classical" regions as Stassfurt (Germany), Wieliczka (Poland), or California (USA). Another spectacular mineral given the perfection of its crystals and color variety (violet, green, yellow, etc.) is fluorite, present in the collection by means of samples from Romania (Cavnic, Banat) and abroad (Germany, United Kingdom, etc.). The green crystals of 2.5 cm of atacamite (Chile) also catch the eye.
4.Oxides and hydroxides. This group includes some of the most common minerals of the earth crust (approximately 17% of the total of species, of which 12% are silicon oxides, represented especially by quartz and opal). There are displayed tens of samples of quartz (amethyst, rock crystal, smoky quartz) – including chalcedonies (agate, jasper, etc.) as well as opal (noble, fire, opalized wood) from Romania and abroad. Other gems of this class are represented by the noble varieties of corundum (sapphire, ruby) and chrysoberyl. Magnetite and hematite are the main iron minerals; in Romania, they are exploited especially in Banat (for example, Ocna de Fier) or at Maşca-Băişoara, Cluj county.
5.Nitrates, carbonates, borates. The best represented mineral in this exhibition is calcite, with colorless and perfectly transparent crystals (including Iceland spar), pink (containing manganese), or – the „specialty" of the Baia Mare region – black or (black and white). The twin crystals of aragonite from Spania Dolina (Slovakia), of up to 7 cm, or from Corund, Harghita county (1-2 cm) are among rarities. Two copper minerals, vividly colored - azurite (blue) and malachite (green) also retain the visitor's attention. Among the rare species are the ludwigite from Ocna de Fier, Caraș-Severin county as well as the szaibelyite and kotoite from Băiţa, Bihor county, minerals described for the first time in Romanian literature.
6.Sulfates, chromates, molybdates, wolframates. The perfect crystals of celestine from Copăceni or Cluj stand aside those from abroad (Germany, Italy, France, USA, etc.). Barite is another spectacular mineral due to its lamellar crystals disposed in rosettes (for example, from the Baia Mare region), or, more rarely, in columns (France, United Kingdom, USA). Gypsum appears either with a massive structure - alabaster, or as crystals of various shapes and sizes. The visitor's attention is also drawn by crocoite (Tasmania, Australia), with its fiery red, or the copper sulfates (chalcanthite, devilline, etc.), with diverse tones of blue and green.
7.Phosphates, arsenates, vanadates. Apatite crystals of various shapes and colors, from renowned occurrences around the world (Canada, Germany, Czech Republic, Austria, Norway, etc.) are displayed next to rare species, some of them having been described in Romania (for example, the krautite from Săcărâmb, Hunedoara county). The attention is also drawn by the vivid blue and green tones of the copper phosphates and arsenates (turquoise, lavendulan, etc.).
8.Silicates. This is the class with the highest number of mineral species (over 25% of the total), their share in nature being much more significant (they account for approximately 80% of the earth crust). Generally, they are transparent and hard minerals; when they are vividly colored, they can be used as ornamental gemstones: garnets, topaz, beryl (with the varieties of emerald and aquamarine), tourmaline, jadeite and nephrite (both known under the name of „jade"), etc. The majority comes from well-known regions around the world (Russia – Ural Mountains, Italy, Brasil, USA, etc.). Rare minerals, as for example gehlenite – for which Romania keeps the world's "record" concerning the dimension of the crystals, i.e. 15 cm (the collection contains crystals of up to 7 cm) or the tilleyite from Vaţa de Sus, Hunedoara county are of great scientific importance. There is a large variety of feldspars (including "noble" varieties as are amazonite or labradorite).
9.Organic minerals. This is a class with a small number of mineral species, formed by carbon, hydrogen, and oxygen compounds. The most spectacular samples at the Museum are those of amber (succinite) (metaphorically called also ”the tear of the gods") from Colţi, Buzău county, and from Vălenii de Munte, Prahova county. This mineral occurred as a result of the transformation along time of some natural vegetal resins; it can sometimes include, in its initial phases, insects or other fossil animals. In addition, there are displayed different types of coal – combustible organic rocks consisting of the organic substance rich in carbon, obtained as result of the transformation of fossil plants.
