Zhivka Janakieva's Photo Gallery
975-CF1Bertrandite Be4(Si2O7)(OH)2
Very well defined bertrandite crystal with platy muscovite. The bertrandite crystals have prismatic habit and their size varies from 30 to 100 microns. Collected in 2007. Photo and collection Zh.Janakieva.
During the study of the ore samples from Krushev dol, Madan district, Bulgaria (january 2007), kept in the Earth & Man National Museum, the occurrence of the minerals helvite and bertrandite has been proven. In the study of these minerals we have used microscopic, physical and chemical research methods. The X-ray tests were conducted using an X-ray diffractometer TUR M 62 (CuKalpha radiation and Ni filter), and the parameters of the unit cell were calculated using the Unit Cell software. For SEM studies a JEOL JSM 35 CF was used.
Mindat.org Photo of the Day - 4th Oct 2011
JV3-P4THelvine Be3Mn2+4(SiO4)3S
Tetrahedral, very well defined Helvite (20 mm) with quartz. Collected in 2007. Photo Zh.Janakieva, collection of “Earth and Man” National Museum, Sofia
During the study of the ore samples from Krushev dol, Madan district, Bulgaria (january 2007) kept in the “Earth and Man” National Museum, Sofia the existence of minerals helvite has been proven. In the study of these minerals we have used microscopic, physical and chemical research methods. The x-ray tests were conducted using an x-ray diffraction-meter TUR M 62, at CU radiation and Ni filter, and the parameters of the elementary cell were calculated using Unit Cell software. For SEM – using JEOL JSM 35 CF.
