Article

Emerald is a precious gemstone and a variety of the mineral beryl [Be3Al2(SiO3)6] colored green by trace amounts of chromium and sometimes vanadium. It is…

Hydrokenoelsmoreite is a hydrous tungsten oxide mineral with formula □2W2O6(H2O). It forms from the oxidation of ferberite within granitic pegmatite dykes and in pegmatitic greisen…

Internal Recruitment involves recruiting candidates from those who are already in employment within the organization. It is concerned with recruiting people internally through transfer and…

Eveslogite (Ca,K,Na,Sr,Ba)48[(Ti,Nb,Fe,Mn)12(OH)14Si48O144](F,OH,Cl)14] is a complex inosilicate mineral found on Mt. Eveslogchorr in Khibiny massif, Kola Peninsula, Russia. It is a monoclinic-prismatic mineral containing aluminum, barium,…

Evenkite is a rare hydrocarbon mineral with formula (CH3)2(CH2)22 or C24H50. Chemically it is n-tetracosane. It is a rare hydrocarbon mineral. It was first discovered…

Eveite is a manganese arsenate mineral in the olivenite group. Its chemical formula is Mn2AsO4OH. It is an orthorhombic-dipyramidal apple-green mineral containing arsenic, hydrogen, manganese,…

Theorem of Three Perpendiculars A line is said to be perpendicular to another line if the two lines intersect at a right angle. Explicitly, a…

Euxenite or euxenite-(Y) is a brownish black mineral with a metallic luster. It is a mineral that is sometimes called a “trash can mineral”. Because…

Zirsilite-(Ce) is a very rare mineral of the eudialyte group, with formula (Na,[])12(Ce, Na)3 Ca6 Mn3Zr3NbSi(Si9O27)2(Si3O9)2O(OH)3(CO3)•H2O. The original formula was extended to show the presence…

Voronkovite is a very rare mineral of the eudialyte group with the formula Na15(Na, Ca, Ce)3(Mn, Ca)3Fe3Zr3Si2Si24O72(OH, O)4Cl·H2O. It is a trigonal-pyramidal yellowish-brown mineral containing…

Converse of the theorem on parallel lines and plane: Theorem: If two straight lines are parallel and if one of them is perpendicular to a…

Taseqite is a rare mineral of the eudialyte group, with formula Na12Sr3Ca6Fe3Zr3NbSiO(Si9 O27)2(Si3O9)2(O, OH, H2O)3Cl2. It occurs in a cavity in a late-stage hydrothermal albitite…