It is found in Amhurst Co., Virginia, adherent to the allanite which occurs there in large quantities. It was discovered there by Mallet in 1877, who named it, on account of the columbium (niobium) present, from Sipylus, one of the sons of Niobe.[68] [68] See Mallet, _Amer. J. Sci._ 1877, [iii.], ~14~, 397. * * * * * In this class, also, are to be included the following minerals (see list): _Nohlite_ and _Vietinghofite_, varieties of Samarskite. _Hjelmite_ and _Kochelite_, minerals closely related to Yttrotantalite and Fergusonite respectively. _Koppite_, _Loranskite_, _Microlite_ and _Rogersite_, complex tantalo-columbates containing elements of the cerium or yttrium groups. (_b_) TANTALO-COLUMBATES CONTAINING TITANIUM DIOXIDE ~Æschynite.~--A columbate and titanate of the cerium metals, with thorium, calcium, iron, etc. From the results of an analysis on a specimen from Hitterö, Norway, Tschernik proposed the rather formidable formula 2(2Ce₂O₃,3TiO₂),4(ThO₂,TiO₂),Y₂(CbO₃)₆,3(CaO,TiO₂),3Fe(CbO₃)₂, Fe(TaO₃)₂,6TiO₂. This can be simplified to Y(CbO₃)₃ + ThTiO₄ + ³⁄₂TiO₂, in which Y represents rare earth metals partially replaced (2 atoms) by ferrous iron (3 atoms), whilst thorium can be partially replaced by (2 atoms of) ferrous iron or calcium. Strutt found it to contain the uranium-radium combination and helium. The crystals are orthorhombic, holosymmetric; _a_ : _b_ : _c_ = 0·4866 : 1 : 0·6737. Common forms--brachy- and basal pinakoids _b_ {010} and _c_ {001}, prisms _m_ {110} and _r_ {120}, domes _d_ {101} and _v_ {021}, with pyramid _o_ {111}. (100) ∧ (110) = 25° 57´; (001) ∧ (101) = 54° 9´; (001) ∧ (011) = 33° 58´. Habit prismatic, vertically striated, or tabular parallel to b with horizontal striations. Brittle. Hardness 5 to 6; sp. gr. 4·9 to 5·7. Colour nearly black. Nearly opaque. It occurs at Miask, in the Urals, at Hitterö in Norway, and at Fredriksvarn. The variety from the last locality is called Polymignite; it was shown by Rose to be probably identical with Æschynite. Æschynite was discovered by Berzelius at Miask and named by him from the Greek αίσχύνη, shame, from the fact that its composition could not at that time be determined. If the ceria earths be largely replaced by yttria earths, a variety very similar in appearance and angles, but approximating to polycrase (_q.v._) in composition, is obtained. This mineral was found in 1879, and referred to Æschynite; analysis subsequently showed its true composition, and it was named Blomstrandine (_q.v._) by Brögger in 1907. _The Isodimorphous Series Euxenite, Polycrase, Blomstrandine, and Priorite._