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"This form consists of twelve scalene triangular faces. These faces correspond in their position to the alternate pairs of faces of a dihexagonal pyramid." — Ford, 1912

Scalenohedron

"This form consists of twelve scalene triangular faces. These faces correspond in their position to…

"...bounded by twelve scalene triangles, and with the general indices {hkl}." -The Encyclopedia Britannica 1910

Scalenohedron

"...bounded by twelve scalene triangles, and with the general indices {hkl}." -The Encyclopedia Britannica…

Principal forms of the hexagonal system: scalenohedron

Scalenohedron

Principal forms of the hexagonal system: scalenohedron

"The zig-zag lateral edges [of a scalenohedron] coincide with the similar edges of a rhombohedron..." -The Encyclopedia Britannica 1910

Scalenohedron with inscribed Rhombohedron

"The zig-zag lateral edges [of a scalenohedron] coincide with the similar edges of a rhombohedron..."…

This crystal of Tourmaline exhibits hemimorphism in the direction of the vertical axis. Its forms are the prisms, (g), which as a result of hemimorphism, appear as a trigonal prism, and (a); the scalenohedron, (s), and the two rhombohedrons, (R) and (r), at the antilogue pole, while only (R) occurs at the analogue pole.

Tourmaline

This crystal of Tourmaline exhibits hemimorphism in the direction of the vertical axis. Its forms are…