Kazakovite

Pale yellow radioactive mineral
(repeating unit)Na6Mn2+Ti(Si6O18)IMA symbolKzk[1]Strunz classification9.CJ.15aDana classification61.1.2a.2Crystal systemTrigonalCrystal classHexagonal scalenohedral
H-M symbol: (3 2/m)Space groupR 3mUnit cell1,168.92IdentificationColorPale yellowTwinningSimple, complex, and polysynthetic twins, axis normal to (1124)CleavageNoneFractureIrregular/uneven, conchoidalMohs scale hardness4LusterVitreous, greasyStreakWhiteDiaphaneityTransparentSpecific gravity2.84Density2.84Optical propertiesUniaxial (−)Refractive indexnω = 1.648 – 1.650
nε = 1.625 – 1.638Birefringence0.023Common impuritiesAl, Fe, Nb, Mg, Ca, K, P, H2OOther characteristics Radioactive

Kazakovite was named in honor of Maria Efimovna Kazakova analytical chemist. It is a type locality of Karnasurt mountain, Lovozersky District, Murmansk Oblast, Russia.[2] It was approved by the IMA in 1974, the same year it was discovered.[3]

Properties

Kazakovite is a cation-saturated member of the lovozerite group and the zirsinalite-lovozerite subgroup. It occurs in sodalite syenites, and disseminated in ussingite. X-ray studies show the mineral to be rhombohedral. It occurs as small crystals (0.01 – 2 mm), and is showing the forms {1121} and {1124}.[4] Kazakovite mainly consists of oxygen (44.59%), silicon (25.65%) and sodium (19.58%), but also contains titanium (4.45%), manganese (3.40%), iron (1.73%) and potassium (0.61%). It has a barely detectable, 8.56 radioactivity measured in Gamma Ray American Petroleum Institute Units. It is radioactive due to containing potassium, even though in low amounts. The concentration measured in GRapi is 11.68%.[5]

Tisinalite

After its discovery, it was quickly noticed the mineral is unstable in air. The mineral became covered in efflorescence of natron and thermonatrite after several days in room conditions. After special experimental studies, it was found that the mineral alters in air into H-kazakovite, better known as tisinalite. The process is complete after several weeks of exposure to moist air.[6]

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ "Kazakovite". www.mindat.org. Retrieved 2021-08-08.
  3. ^ "KAZAKOVITE". euromin.w3sites.net. Retrieved 2021-08-08.
  4. ^ Fleischer, Michael (1975). "New Mineral Names" (PDF). American Mineralogist. 060: 161–162.
  5. ^ "Kazakovite Mineral Data". webmineral.com. Retrieved 2021-08-08.
  6. ^ Pekov, Igor V.; Krivovichev, Sergey V.; Zolotarev, Andrey A.; Yakovenchuk, Viktor N.; Armbruster, Thomas; Pakhomovsky, Yakov A. (September 2009). "Crystal chemistry and nomenclature of the lovozerite group" (PDF). {{cite journal}}: Cite journal requires |journal= (help)