"Tetragonal. Usually shows a combination of prism of second order, pyramid of first and basal plane." — Ford, 1912

Apophyllite

"Tetragonal. Usually shows a combination of prism of second order, pyramid of first and basal plane."…

"Tetragonal. Common forms are prisms and pyramids of first and second orders." — Ford, 1912

Cassiterite

"Tetragonal. Common forms are prisms and pyramids of first and second orders." — Ford, 1912

Combination of holohedral tetragonal forms.

Combination of Tetragonal Prism and Basal Pinacoid

Combination of holohedral tetragonal forms.

Illustration showing tetragonal combination forms.

Tetragonal Combinations

Illustration showing tetragonal combination forms.

Illustration showing a tetragonal deuteropyramid.

Tetragonal Deuteropyramid

Illustration showing a tetragonal deuteropyramid.

Illustration showing a ditetragonal pyramid.

Ditetragonal Pyramid

Illustration showing a ditetragonal pyramid.

"Tetragonal. Usually prismatic with pyramid terminations." — Ford, 1912

Rutile

"Tetragonal. Usually prismatic with pyramid terminations." — Ford, 1912

"Tetragonal; tri-pyramidal. Crystals usually simple pyramids of first order. Closely resemble isometric octahedrons in angles. Faces of the pyramid of third order are small and rare." — Ford, 1912

Scheelite

"Tetragonal; tri-pyramidal. Crystals usually simple pyramids of first order. Closely resemble isometric…

A tetragonal bipyramidal crystal where the vertical axis is shorter than the horizontal axes.

Tetragonal Bipyramids

A tetragonal bipyramidal crystal where the vertical axis is shorter than the horizontal axes.

A tetragonal bipyramidal crystal where the vertical axis is longer than the horizontal axes.

Tetragonal Bipyramids

A tetragonal bipyramidal crystal where the vertical axis is longer than the horizontal axes.

Represents the relation between the tetragonal bipyramid of the first order when the indices are {111}.

Tetragonal Bipyramids of the First Order

Represents the relation between the tetragonal bipyramid of the first order when the indices are {111}.

Represents the relation between the tetragonal bipyramid of the first order when the indices are {111}.

Tetragonal Bipyramids of the Second Order

Represents the relation between the tetragonal bipyramid of the first order when the indices are {111}.

"This is bounded by eight scalene triangesl and has the indices{hkl}. It may be considered as the hemihedral form of the ditetragonal bipyramid." -The Encyclopedia Britannica 1910

Tetragonal Scalenohedron

"This is bounded by eight scalene triangesl and has the indices{hkl}. It may be considered as the hemihedral…

"The trapezohedron is a form composed of twenty-four trapezium-shaped faces, each of which intersects one of the crystallographic axes at unity and the other two at equal multiples." — Ford, 1912

Trapezohedron

"The trapezohedron is a form composed of twenty-four trapezium-shaped faces, each of which intersects…

"Tetragonal. Prismatic in habit. Often vertically striated. Common forms are prisms of first and second orders, pyramid of first order and base." — Ford, 1912

Vesuvianite

"Tetragonal. Prismatic in habit. Often vertically striated. Common forms are prisms of first and second…