"Hexagonal. Strong prismatic habit. Frequently vertically striated and grooved. Forms usually present consist only of prism of first order and base. Small pyramid faces of both the first and second orders sometimes occur, but the pyramid faces are rarely prominent." — Ford, 1912

Beryl

"Hexagonal. Strong prismatic habit. Frequently vertically striated and grooved. Forms usually present…

Holohedral; Dihexagonal bipyramidal

Combination of Hexagonal Forms

Holohedral; Dihexagonal bipyramidal

Holohedral; Dihexagonal bipyramidal

Combination of Hexagonal Forms

Holohedral; Dihexagonal bipyramidal

"Hexagonal-rhombohedral. Crystals usually prismatic in habit or tapering hexagonal pyramids." — Ford, 1912

Corundum

"Hexagonal-rhombohedral. Crystals usually prismatic in habit or tapering hexagonal pyramids." —…

"Hexagonal-rhombohedral. Crystals usually prismatic in habit or tapering hexagonal pyramids." — Ford, 1912

Corundum

"Hexagonal-rhombohedral. Crystals usually prismatic in habit or tapering hexagonal pyramids." —…

"...represents a crystal of dioptase with the fundamental rhombohedron (r) and the hexagonal prism of the second order (m) combined with the rhombohedron (s)." -The Encyclopedia Britannica 1910

Crystal of Dioptase

"...represents a crystal of dioptase with the fundamental rhombohedron (r) and the hexagonal prism of…

Principal forms of the hexagonal system: dihexagonal prism

Dihexagonal Prism

Principal forms of the hexagonal system: dihexagonal prism

Principal forms of the hexagonal system: dihexagonal pyramid.

Dihexagonal Pyramid

Principal forms of the hexagonal system: dihexagonal pyramid.

Principal forms of the hexagonal system: ditrigonal prism

Ditrigonal Prism

Principal forms of the hexagonal system: ditrigonal prism

A flashcard featuring an illustration of a Pyramid with a Hexagonal Base

Flashcard of a Pyramid with a Hexagonal Base

A flashcard featuring an illustration of a Pyramid with a Hexagonal Base

"The second form of carbon, known as graphite, is a leaden-gray solid with a metallic luster and a specific gravity of 2 to 2.2, which crystallizes." —Hallock 1905

Graphite

"The second form of carbon, known as graphite, is a leaden-gray solid with a metallic luster and a specific…

"Hexagonal-rhombohedral. Crystals usually thick to thin tabular. Basal planes prominent, often showing triangular markings." — Ford, 1912

Hematite

"Hexagonal-rhombohedral. Crystals usually thick to thin tabular. Basal planes prominent, often showing…

"Hexagonal-rhombohedral. Crystals usually thick to thin tabular. Basal planes prominent, often showing triangular markings." — Ford, 1912

Hematite

"Hexagonal-rhombohedral. Crystals usually thick to thin tabular. Basal planes prominent, often showing…

"...bounded by twelve isosceles trianes each of which are equally inclined to two planes of symmetry." -The Encyclopedia Britannica 1910

Hexagonal Bipyramid

"...bounded by twelve isosceles trianes each of which are equally inclined to two planes of symmetry."…

"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

Hexagonal Prism

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

"...shows a combination of a hexagonal prism (m) with the basal pinacoid (c)." -The Encyclopedia Britannica 1910

Hexagonal Prism and Basal Pinacoid

"...shows a combination of a hexagonal prism (m) with the basal pinacoid (c)." -The Encyclopedia Britannica…

Principal forms of the hexagonal system: hexagonal prism

Hexagonal Prism First Order

Principal forms of the hexagonal system: hexagonal prism

"Hexagonal prism of the first order, consisting of six faces also parallel to the hexad axis, but perpendicular to the other set of three vertical planes of symmetry." -The Encyclopedia Britannica 1910

Hexagonal Prism of the First Order

"Hexagonal prism of the first order, consisting of six faces also parallel to the hexad axis, but perpendicular…

Principal forms of the hexagonal system: hexagonal prism

Hexagonal Prism Second Order

Principal forms of the hexagonal system: hexagonal prism

Principal forms of the hexagonal system: hexagonal pyramid.

Hexagonal Pyramid First Order

Principal forms of the hexagonal system: hexagonal pyramid.

Principal forms of the hexagonal system: hexagonal pyramid.

Hexagonal Pyramid Second Order

Principal forms of the hexagonal system: hexagonal pyramid.

A hexagonal flower stand made out of reed.

Jardiniere Stand

A hexagonal flower stand made out of reed.

"The symmetry of the Normal Class of the Hexagonal System is as follows: The vertical crystallographic axis is an axis of hexagonal symmetry. There are six horizontal axes of binary symmetry, three of them being coincident with the crystallographic axes and the other three lying midway between them." — Ford, 1912

Symmetry of normal class

"The symmetry of the Normal Class of the Hexagonal System is as follows: The vertical crystallographic…

Illustration of a right hexagonal prism.

Hexagonal Prism

Illustration of a right hexagonal prism.

Illustration of a right hexagonal prism with hidden edges shown.

Hexagonal Prism

Illustration of a right hexagonal prism with hidden edges shown.

Illustration of a right hexagonal prism with a height less than the length of the edge of the hexagon.

Hexagonal Prism

Illustration of a right hexagonal prism with a height less than the length of the edge of the hexagon.

Illustration of a right hexagonal prism with a height greater than the length of the edge of the hexagon.

Hexagonal Prism

Illustration of a right hexagonal prism with a height greater than the length of the edge of the hexagon.

Illustration of a right hexagonal prism with hexagons for bases and square faces.

Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and square faces.

Illustration of a right hexagonal prism with hexagons for bases and square faces. The hidden edges are shown.

Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and square faces. The hidden edges are…

Illustration of a right hexagonal prism with hexagons for bases and rectangular faces. The height of the prism is greater than the length of a side of the hexagon. The hidden edges are shown.

Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and rectangular faces. The height of…

A cluster of 4 right hexagonal prisms with congruent bases, but varying heights.

4 Hexagonal Prisms

A cluster of 4 right hexagonal prisms with congruent bases, but varying heights.

"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

Rhombohedron

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

Principal forms of the hexagonal system: rhomohedron.

Rhombohedron

Principal forms of the hexagonal system: rhomohedron.

Principal forms of the hexagonal system: scalenohedron

Scalenohedron

Principal forms of the hexagonal system: scalenohedron

"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

Six-sided Pyramid

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

Principal forms of the hexagonal system: trigonal prism

Trigonal Prism

Principal forms of the hexagonal system: trigonal prism