Defn: A sulphide of antimony and copper, with small quantities of other metals. It is a very common ore of copper, and some varieties yield a considerable presentage of silver. Called also gray copper ore, fahlore, and panabase.
TETRAHEDRON
Tet`ra*he"dron, n. Etym: [Tetra- + Gr. (Geom.)
Defn: A solid figure inclosed or bounded by four triangles.
Note: In crystallography, the regular tetrahedron is regarded as the hemihedral form of the regular octahedron. Regular tetrahedron (Geom.), a solid bounded by four equal equilateral triangles; one of the five regular solids.
TETRAHEXAHEDRAL
Tet`ra*hex`a*he"dral, a. (Crystallog.)
Defn: Pertaining to a tetrahexahedron.
TETRAHEXAHEDRON
Tet`ra*hex`a*he"dron, n. Etym: [Tetra- + hexahedron.] (Crystallog.)
Defn: A solid in the isometric system, bounded by twenty-four equal triangular faces, four corresponding to each face of the cube.
TETRAKISHEXAHEDRON
Tet`ra*kis*hex`a*he"dron, n. Etym: [Gr. hexahedron.] (Crystallog.)
Defn: A tetrahexahedron.