The combination of an icositetrahedron and an octahedron.

Combination of Icosietetrahedron and Octahedron

The combination of an icositetrahedron and an octahedron.

"...resembles in general appearance the regular icosahedron of geometry, but only eight f the faces are equalateral trianges." -The Encyclopedia Britannica 1910

Combination of Pentagonal Dodecahedron and Octahedron

"...resembles in general appearance the regular icosahedron of geometry, but only eight f the faces…

Represents the combination of pentagonal dodecahedron, cube, and octahedron.

Combination of Pentagonal Dodecahedron, Cube and Octahedron

Represents the combination of pentagonal dodecahedron, cube, and octahedron.

Represents the combination of pentagonal dodcahedron, dyakis-dodecahedron and octahedron.

Combination of Pentagonal Dodecahedron, Dyakis-dodecahedron, and Octahedron

Represents the combination of pentagonal dodcahedron, dyakis-dodecahedron and octahedron.

The combination of a cube and a triakis-octahedron.

Combination of Triakis-octahedron and cube

The combination of a cube and a triakis-octahedron.

Represents the combination of an octrahedron and a cube, with the cube faces predominate.

Cube in Combination with Octahedron

Represents the combination of an octrahedron and a cube, with the cube faces predominate.

A cube, octahedron, and dodecahedron.

Cube, octahedron and dodecahedron

A cube, octahedron, and dodecahedron.

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be trunctuated by the second." — Ford, 1912

Octahedron trunctuated by cube

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be…

Represents the combination of a cube and an octahedron, with both faces being equal.

Cubo-octahedron

Represents the combination of a cube and an octahedron, with both faces being equal.

A dodecahedron and octahedron

Dodecahedron and octahedron

A dodecahedron and octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which belongs a number of forms having some property in common. In order to classify these different crystals, the existence of certain lines within the crystal, called axes, is assumed, around which the form can be symmetrically build up. These axes are assumed to intersect in the center of the crystal, and to pass through from one side to the other." — Hallock, 1905

First Right Square Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

Illustration showing the combination of a hexahedron and an octahedron.

Hexahedron and Octahedron

Illustration showing the combination of a hexahedron and an octahedron.

Illustration showing the combination of a hexahedron and an octahedron.

Hexahedron and Octahedron

Illustration showing the combination of a hexahedron and an octahedron.

A polyhedron with eight faces.

Octahedron

A polyhedron with eight faces.

"Right octahedron with rhombic base." — Hallock, 1905

Octahedron

"Right octahedron with rhombic base." — Hallock, 1905

"Right octahedron with rhombic base." — Hallock, 1905

Octahedron

"Right octahedron with rhombic base." — Hallock, 1905

"Oblique rhombic octahedron." — Hallock, 1905

Octahedron

"Oblique rhombic octahedron." — Hallock, 1905

An octahedron, or double four-sided pyramid. It has 8 sides.

Octahedron

An octahedron, or double four-sided pyramid. It has 8 sides.

Illustration showing a perfect octahedron.

Octahedron

Illustration showing a perfect octahedron.

Principal forms of the isometric system: octahedron.

Octahedron

Principal forms of the isometric system: octahedron.

A combination of octahedron and dodecahedron.

Octahedron and dodecahedron

A combination of octahedron and dodecahedron.

Illustration showing the combination of a octahedron and an dodecahedron.

Octahedron and Dodecahedron

Illustration showing the combination of a octahedron and an dodecahedron.

"Combiantion of pyritohedron and octahedron." — Ford, 1912

Octahedron and pyritohedron

"Combiantion of pyritohedron and octahedron." — Ford, 1912

"A combination of pyritohedron and octahedron." — Ford, 1912

Octahedron and pyritohedron

"A combination of pyritohedron and octahedron." — Ford, 1912

"A combination of a trisoctahedron and an octahedron. It will be noted that the faces of the trisoctahedron bevel the edges of the ocrahedron." — Ford, 1912

Octahedron and trisoctahedron

"A combination of a trisoctahedron and an octahedron. It will be noted that the faces of the trisoctahedron…

Represents the combination of an octahedron and a cube, with the octahedron predominate.

Octahedron in Combination with Cube

Represents the combination of an octahedron and a cube, with the octahedron predominate.

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be trunctuated by the second." — Ford, 1912

Cube trunctuated by octahedron

"When a corner or an edge of one form is replaced by a face of another form, the first is said to be…

A distorted octahedron.

Distorted octahedron

A distorted octahedron.

Pattern that can be cut out and folded to construct a regular octahedron. Fold on the dotted lines, and keep the edges in contact by the glued strips of paper.

Pattern for Octahedron

Pattern that can be cut out and folded to construct a regular octahedron. Fold on the dotted lines,…

Illustration showing the derivation of Tetrahedron from an Octahedron.

Tetrahedron From Octahedron

Illustration showing the derivation of Tetrahedron from an Octahedron.

"A contact twin, since the two individuals lie simply in contact with each other upon a certain plane." — Ford, 1912

Twinned octahedron

"A contact twin, since the two individuals lie simply in contact with each other upon a certain plane."…

Illustration of regular polyhedrons: tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron.

Regular Polyhedrons

Illustration of regular polyhedrons: tetrahedron, hexahedron, octahedron, dodecahedron, icosahedron.

"Right rhombic prism." — Hallock, 1905

Prism

"Right rhombic prism." — Hallock, 1905

"Doubly oblique prism." — Hallock, 1905

Prism

"Doubly oblique prism." — Hallock, 1905

"A combination of pyritohedron and octahedron." — Ford, 1912

Pyritohedron and octahedron

"A combination of pyritohedron and octahedron." — Ford, 1912

"A cube trunctuated with pyritohedron and octahedron." — Ford, 1912

Pyritohedron, cube, and octahedron

"A cube trunctuated with pyritohedron and octahedron." — Ford, 1912

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which belongs a number of forms having some property in common. In order to classify these different crystals, the existence of certain lines within the crystal, called axes, is assumed, around which the form can be symmetrically build up. These axes are assumed to intersect in the center of the crystal, and to pass through from one side to the other." — Hallock, 1905

Regular Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which belongs a number of forms having some property in common. In order to classify these different crystals, the existence of certain lines within the crystal, called axes, is assumed, around which the form can be symmetrically build up. These axes are assumed to intersect in the center of the crystal, and to pass through from one side to the other." — Hallock, 1905

Second Right Square Octahedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

Illustration containing a tetrahedron, hexahedron, octahedron, dodecahedron, and icosahedron, placed next to each other.

Various Solid Forms

Illustration containing a tetrahedron, hexahedron, octahedron, dodecahedron, and icosahedron, placed…

"An octahedron twinned on an octahedral face has the two portions symmetrical with repsect to a plane parallel to this face (the large triangular face in this figure)." -The Encyclopedia Britannica 1910

Spinel-twin

"An octahedron twinned on an octahedral face has the two portions symmetrical with repsect to a plane…

"One allotropic forms of sulphur, that of a lemon-yellow brittle solid, crystallizing in orthorhombic octahedrons." —Hallock 1905

Suphur

"One allotropic forms of sulphur, that of a lemon-yellow brittle solid, crystallizing in orthorhombic…

"This solid is bounded by twenty-four isosceles triangles, and may be considered as an octahedron with a low triangular pyramid on each of its faces." -The Encyclopedia Britannica 1910

Triakis-octahedron

"This solid is bounded by twenty-four isosceles triangles, and may be considered as an octahedron with…

An illustration showing "two octahedra...united by contact along a surface parallel to an octahedron face without interpentration. " -Britannica, 1910

Two Octahedra

An illustration showing "two octahedra...united by contact along a surface parallel to an octahedron…