1. Mineralogical exhibition of Mátra Museum

2. Minerals of sedimentary rocks of the Mátra Mountains

4. 1. Native sulphur (S)

5. Native sulphur– S Class: Native elements Subclass: Semimetallic and nonmetallic Crystal system: rhombic Characteristic crystal form: dipyramidal Hardness: 1,5 – 2,5 Cleavage/Fracture: conchoidal cleavage/uneven fracture Colour: yellow, greenish Streak colour: white Glance: resinous, greasy lustre Locality: Visonta

6. 2. Salmiac (HN 4 Cl)

7. Salmiac – HN 4 Cl Class: Halides Crystal system: cubic Characteristic crystal form: rombdodecahedral Hardness: 1 – 2 Cleavage/Fracture: moderated cledavage/uneven fracture Colour: colourless, white, yellowish Streak colour: colourless Glance: glassy lustre Locality: Szurdokpüspöki

8. 3. Opal (SiO 2 ∙nH 2 O)

9. Opal – SiO 2 ∙nH 2 O Class: Oxides and Hidroxides Crystal system: amorph Characteristic crystal form: botryoidal, massive, geode Hardness: 5,5 – 6,5 Cleavage/Fracture: no cleavage/conchoidal fracture Colour: colourless, white, red, brown Streak colour: white Glance: glassy, unglazed, earthy, waxy lustre Locality: Mátraverebély

10. 4. Calcite (CaCO 3 )

11. Calcite – CaCO 3 Class: Carbonates, Nitrates Crystal system: trigonal Characteristic crystal form: rombohedral, prismatic, tabular Hardness: 3 Cleavage/Fracture: excellent cleavage/conchoidal fracture Colour: colourless, white, grey, brown, yellow Streak colour: white Glance: glassy, pearly lustre Locality: Parádfürdő

12. 5. Gypsum (CaSO 4 ∙2H 2 O)

13. Gypsum – CaSO 4 ∙2H 2 O Class: Sulfates Crystal system: monoclinic Characteristic crystal form: tabular, prismatic Hardness: 1,5 – 2 Cleavage/Fracture: excellent cleavage/conchoidal fracture Colour: colourless, white, grey, yellowish Streak colour: colourless Glance: glassy to pearly lustre Locality: Visonta

14. 6. Diadochite (Fe 2 [(SO 4 )(PO 4 )(OH)]∙6H 2 O)

15. Diadochite – Fe 2 (SO 4 )(PO 4 )(OH)∙6H 2 O Class: Sulfates Crystal system: triclinic Characteristic crystal form: earthy Hardness: 3-4 Cleavage/Fracture: no cleavage/uneven fracture Colour: yellow, yellowish brown Streak colour: white Glance: unglazed Locality: Szurdokpüspöki

16. 7. Glauconite [(K,Na) 0,6-0,85 )(Fe 3+,Al,Mg,Fe 2+ ) 2 [(Si,Al) 4 O 10 ](OH) 2 ] Glauconite [(K,Na) 0,6-0,85 )(Fe 3+,Al,Mg,Fe 2+ ) 2 [(Si,Al) 4 O 10 ](OH) 2 ]

17. Glauconite – [(K,Na) 0,6-0,85 )(Fe 3+,Al,Mg,Fe 2+ ) 2 [(Si,Al) 4 O 10 ](OH) 2 Class: Silicates Subclass: Fillosilicates Crystal system: monoclinic Characteristic crystal form: earthy, squamous Hardness: 2 Cleavage/Fracture: excellent cleavage/uneven fracture Colour: green, light green Streak colour: green Glance: unglazed Locality: Mátraderecske