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24 RUBY FAMILY. 1. Automate. Automolith, Werner. Automalit, Eckeberg, in N. Allgem. Journal der Chemie, 5. B. s. 422, 435. Automalit, Corindon zincifere, Jour, de Phys. an 14, p. 270—Automalit & Fahlunit, Karst. Tabel. p 102. —Gahnite, Von Moll.—Spinellc zincifere, liauy, Tab], p. 67, Automalith, Steffens, b. i. s. 32. External Characters. Its colour is muddy duck-blue, which inclines very much to mountain-green. It has been hitherto found only crystallised, and in the following figures: 1. Perfect octahedron. 2. Octahedron, with alternate larger and smaller planes. 3. Tetrahedron, truncated on the angles. 4. Segment of the tetrahedron. 5. Two segments, N" 4. joined together, so that re entering angles are formed on the three corners of the figure. The crystals are small and middle-sized; all around crystallised : and the planes are smooth. Externally it is glistening ; and the lustre is pearly, inclining to semi-metallic. Internally it is shining on the principal fracture, but glistening on the cross frac ture, and the lustre is resinous. llie fracture is foliated, and exhibits a fourfold clea vage, parallel with the planes of the octahedron : a flat conchoidal fracture is also to be observed. The fragments are splintery, or angular, and not very sharp-edged. It is opaque, or faintly translucent on the edges. It is so hard as to scratch quartz. It