This science ClipArt gallery offers 311 illustrations of crystals of numerous minerals. These crystalline minerals are created through natural processes, and so often times there are numerous crystal shapes for any given mineral (polycrystalline materials).

"...take any three edges formed by the intersection of three faces of a crystal. These axes are called the crystallographic axes, and the planes in which they lie are the axial planes. A fourth face on the crystal intersecting these three axes in the points A, B, C is taken as the parametral plan, and the lengths OA:OB:OC are the parameters of the crystal." -The Encyclopedia Britannica 1910

Crystallographic Axes of Reference

"...take any three edges formed by the intersection of three faces of a crystal. These axes are called…

Forms of crystals.

Crystals, Forms of

Forms of crystals.

"A combination of dodecahedron and cube." — Ford, 1912

Cube and dodecahedron

"A combination of dodecahedron and cube." — Ford, 1912

"A combination of cube and hexoctahedron." — Ford, 1912

Cube and hexoctahedron

"A combination of cube and hexoctahedron." — Ford, 1912

"A combination of cube and pyritohedron, in which it will be noted that the faces of the pyritohedron trunctuate unsymmetrically the edges of the cube." — Ford, 1912

Cube and pyritohedron

"A combination of cube and pyritohedron, in which it will be noted that the faces of the pyritohedron…

"A cube with its edges beveled by the faces of a tetrahexahedron." — Ford, 1912

Cube and tetrahexahedron

"A cube with its edges beveled by the faces of a tetrahexahedron." — Ford, 1912

"A combination of cube and trapezohedron." — Ford, 1912

Cube and trapezohedron

"A combination of cube and trapezohedron." — Ford, 1912

Cubes of Iron Pyrites frequently show a striation of their planes in one direction, which is perpendicular to the striation  on all contiguous faces, owing to oscillatory combination with the pentagonal dodecahedron. This would not be possible in a holohedral cube.

Cube of Iron Pyrite

Cubes of Iron Pyrites frequently show a striation of their planes in one direction, which is perpendicular…

A cube, octahedron, and dodecahedron.

Cube, octahedron and dodecahedron

A cube, octahedron, and dodecahedron.

Curvature of crystal planes is quite a constant property of some substances. It may be due to a very fine oscillatory combinations or to an irregularity of growth and a want of perfect parallelism between sub-individuals. A common instance is the Diamond, whose faces, except those of the octahedron, are almost always curved.

Curvature of Crystal Planes (Diamond)

Curvature of crystal planes is quite a constant property of some substances. It may be due to a very…

This crystal of Aragonite shows a method of twinning where the twinning plane may change its direction, as when the two symmetrical faces of a prism successively serve as twinning planes.

Cyclic Twinning

This crystal of Aragonite shows a method of twinning where the twinning plane may change its direction,…

This figure shows an example of cyclic twinning on a crystal of Rutile.

Cyclic Twinning on Rutile

This figure shows an example of cyclic twinning on a crystal of Rutile.

"Monoclinic. Habit varied. Crystals usually nearly equidimensional in the three axial directions and often complex in development." — Ford, 1912

Datolite

"Monoclinic. Habit varied. Crystals usually nearly equidimensional in the three axial directions and…

"Curved faces of the hexoctahedron are frequently observed." — Ford, 1912

Diamond

"Curved faces of the hexoctahedron are frequently observed." — Ford, 1912

Diamond.

Diamond

Diamond.

"Pure crystalline carbon, the hardest substance known, possessing great lustre owing to its great refracting power." — Williams, 1889

Diamond

"Pure crystalline carbon, the hardest substance known, possessing great lustre owing to its great refracting…

The diamond is cut to show the stone's brilliance, creating different parts to the cut: table, crown, girdle, pavilion, culet.

Diamond Cut

The diamond is cut to show the stone's brilliance, creating different parts to the cut: table, crown,…

Various types of square cut diamonds. Top row: Old square cut diamonds. Bottom row: English square cut diamonds.

Square Cut Diamonds

Various types of square cut diamonds. Top row: Old square cut diamonds. Bottom row: English square cut…

Diopside is a monoclinic pyroxene mineral with composition MgCaSi<small><sub>2</sub></small>O<small><sub>6</sub></small>. It forms complete solid solution series with hedenbergite (FeCaSi<small><sub>2</sub></small>O<small><sub>6</sub></small>) and augite, and partial solid solutions with orthopyroxene and pigeonite. It forms variably colored, but typically dull green crystals in the monoclinic prismatic class. It has two distinct prismatic cleavages at 87 and 93&deg; typical of the pyroxene series. It has a Mohs hardness of six and a Vickers hardness of 7.7.

Diopside

Diopside is a monoclinic pyroxene mineral with composition MgCaSi2O6. It forms complete solid solution…

Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is CuSiO<small><sub>3</sub></small>&sdot;H<small><sub>2</sub></small>O (also reported as CuSiO<small><sub>2</sub></small>(OH)<small><sub>2</sub></small>). It has a hardness of 5, the same as tooth enamel. It specific gravity is 3.28&ndash;3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile and specimens must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.

Dioptase

Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent…

Crystal; This form is a combination of an icositetrahedron and a rhombic dodecahedron, where the faces of the icositetrahedron replace the trihedral angles of the dodecahedron. The parameters, m, of the icositetrahedron  are less then two.

Dodecahedron

Crystal; This form is a combination of an icositetrahedron and a rhombic dodecahedron, where the faces…

Crystal; This form is a combination of an icositetrahedron and a rhombic dodecahedron, where the faces of the icositetrahedron replace the trihedral angles of the dodecahedron. The parameters, m, of the icositetrahedron  are less then two.

Dodecahedron

Crystal; This form is a combination of an icositetrahedron and a rhombic dodecahedron, where the faces…

"The faces of the deltoid dodecahedron correspond to one-half those of the trisoctahedron." &mdash; Ford, 1912

Deltoid dodecahedron

"The faces of the deltoid dodecahedron correspond to one-half those of the trisoctahedron." —…

In cases where the basal pinacoid is fixed by some physical property like cleavage, the elongation is in the direction of the clinodiagonal axis. This crystal of Feldspar shown is a common example of this elongation.

Elongation in the Direction of the Clinodiagonal Axis

In cases where the basal pinacoid is fixed by some physical property like cleavage, the elongation is…

In some cases, the elongation of a crystal may be in the direction of the orthogonal axis, whose position is determined by the plane of symmetry. This crystal of the silicate mineral, Epidote, shows an example of this.

Elongation in the Direction of the Orthogonal Axis

In some cases, the elongation of a crystal may be in the direction of the orthogonal axis, whose position…

"...shows two crystals of tartaric acid, a a right-handed crystal of dextro-tartaric acid, and b a left-handed crystal of laevo-tartaric acid. The two crystals are enantimorphous." -The Encyclopedia Britannica 1910

Enantimorphous Crystals of Tartaric Acid

"...shows two crystals of tartaric acid, a a right-handed crystal of dextro-tartaric acid, and b a left-handed…

"Monoclinic. Crystals are often much elongated parallel to the ortho-axis with a prominent development of the faces of the orthodome zone, giving them a prismatic aspect. Striated parallel to the ortho-axis. Terminated usually at one end of the ortho-axis and most commonly by the two faces of a pyramid." &mdash; Ford, 1912

Epidote

"Monoclinic. Crystals are often much elongated parallel to the ortho-axis with a prominent development…

"Positive and negative extinction angles in the feldspars." -Johannsen, 1908

Extinction Angles

"Positive and negative extinction angles in the feldspars." -Johannsen, 1908

Ferrocolumbite, also called niobite, niobite-tantalite, columbate and columbite [(Fe, Mn)(Nb, Ta)2O6] is a black mineral that is an ore of niobium and tantalum. It has a submetallic luster and a high specific gravity and is a niobate of iron and manganese, containing tantalate of iron. This mineral was first found at Haddam, Middlesex County, Connecticut in New England, USA. It forms a series with the tantalum-dominant analogue Ferrotantalite and one with the manganese-dominant analogue Manganocolumbite.

Ferrocolumbite

Ferrocolumbite, also called niobite, niobite-tantalite, columbate and columbite [(Fe, Mn)(Nb, Ta)2O6]…

A combination of the cube (h), the octahedron (o), and the dodecahedron (d).

Galena

A combination of the cube (h), the octahedron (o), and the dodecahedron (d).

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination." &mdash; Ford, 1912

Garnet

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination." — Ford, 1912

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination." &mdash; Ford, 1912

Garnet

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination." — Ford, 1912

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination. Hexoctahedron observed at some times." &mdash; Ford, 1912

Garnet

"Isometric. Common forms dodecahedron amd trapezohedron, often in combination. Hexoctahedron observed…

"Here the plane of projection is tangent to the sphere, and normals to all the faces are drawn fro mthe centre of the sphere to intersect the plane of projection." -The Encyclopedia Britannica 1910

Gnomonic Projection of a Cubic Crystal

"Here the plane of projection is tangent to the sphere, and normals to all the faces are drawn fro mthe…

Gold crystals of the form 3O3, {311}, sometimes resemble combinations of the rhombohedron and scalenohedron.

Gold

Gold crystals of the form 3O3, {311}, sometimes resemble combinations of the rhombohedron and scalenohedron.

Certain crystals of green fluorspar from Saxony, showing the form ∞ 03, {310}, have one half of their planes developed at the expense of the other half, so as to produce a hexagonal scalenohedron.

Green Fluorspar from Saxony

Certain crystals of green fluorspar from Saxony, showing the form ∞ 03, {310}, have one half of their…

Gypsum.

Gypsum

Gypsum.

Gypsum.

Gypsum

Gypsum.

"Monoclinic. Crystals usually tabular parallel to clinopinacoid; in diamond-shaped crystals with edges beveled by prism and pyramid faces." &mdash; Ford, 1912

Gypsum

"Monoclinic. Crystals usually tabular parallel to clinopinacoid; in diamond-shaped crystals with edges…

"Monoclinic. Crystals usually tabular parallel to clinopinacoid; in diamond-shaped crystals with edges beveled by prism and pyramid faces. Other forms rare. Sometimes twinned." &mdash; Ford, 1912

Gypsum

"Monoclinic. Crystals usually tabular parallel to clinopinacoid; in diamond-shaped crystals with edges…

This image represents a twin of the monoclinic mineral Gypsum. Its twinning plane is the orthopinacoid.

Gypsum (Twinning)

This image represents a twin of the monoclinic mineral Gypsum. Its twinning plane is the orthopinacoid.

"Hexagonal-rhombohedral. Crystals usually thick to thin tabular. Basal planes prominent, often showing triangular markings." &mdash; 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." &mdash; 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. Edges of plates sometimes beveled with rhombohedral and pyramidal forms." &mdash; Ford, 1912

Hematite

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

This image shows a hemihedral crystal of pyroxene, whose forms are (c), (b), (a), (m), (o), and (u).

Hemihedral Crystal of Pyroxene

This image shows a hemihedral crystal of pyroxene, whose forms are (c), (b), (a), (m), (o), and (u).

This figure shows hemimorphism in the direction of the axis of symmetry on a crystal of Pentacid Alcohol (C_6_H_12_O_5_). The forms on this crystal are (c), (p), (r), and (q).

Hemimorphism in the Direction of the Axis of Symmetry

This figure shows hemimorphism in the direction of the axis of symmetry on a crystal of Pentacid Alcohol…

Hemimorphism in the direction of the vertical axis has been observed on crystals of the tetragonal salt, Iodosuccinimide (C_4_H_4_O_2_NI, pictured). Its forms are (p), terminated at one end by (o) and (n), and at the other by (o) only.

Hemimorphism in the Direction of the Vertical Axis

Hemimorphism in the direction of the vertical axis has been observed on crystals of the tetragonal salt,…

A disdyakis dodecahedron, or hexakis octahedron, is a Catalan solid and the dual to the Archimedean truncated cuboctahedron. As such it is face-transitive but with irregular face polygons. It looks a bit like an inflated rhombic dodecahedron &mdash; if one replaces each face of the rhombic dodecahedron with a single vertex and four triangles in a regular fashion one ends up with a disdyakis dodecahedron.

Hexakis Octahedron

A disdyakis dodecahedron, or hexakis octahedron, is a Catalan solid and the dual to the Archimedean…

A disdyakis dodecahedron, or hexakis octahedron, is a Catalan solid and the dual to the Archimedean truncated cuboctahedron. As such it is face-transitive but with irregular face polygons. It looks a bit like an inflated rhombic dodecahedron &mdash; if one replaces each face of the rhombic dodecahedron with a single vertex and four triangles in a regular fashion one ends up with a disdyakis dodecahedron.

Hexakis Octahedron

A disdyakis dodecahedron, or hexakis octahedron, is a Catalan solid and the dual to the Archimedean…

This form is bounded by forty-eight similar scalene triangles. Its solid angles are of three kinds: six octahedral, at the extremities of the principal axes; eight hexahedral, at the extremities of the trigonal axes; and twelve tetrahedral, at the extremities of the digonal axes. Naumann's symbol for this form is m 0 n; Dana's, m-n.

Hexoctahedron

This form is bounded by forty-eight similar scalene triangles. Its solid angles are of three kinds:…

This figure reproduces a crystal of Hydrous Copper Sulphate whose forms are (c), (a), (b), (n), (m), (l), and (s).

Hydrous Copper Sulphate

This figure reproduces a crystal of Hydrous Copper Sulphate whose forms are (c), (a), (b), (n), (m),…

This form shows the planes given on a crystal of hydrous nickel sulphate: the basal pinacoid, (c); three pyramids of the second order, (m), (o), and (q); two pyramids of the first order, (n) and (p); and the prisms of the first and second orders, (r) and (s).

Hydrous Nickel Sulphate

This form shows the planes given on a crystal of hydrous nickel sulphate: the basal pinacoid, (c); three…

This figure exhibits a combination occurring on the ferro-magnesian meta-silicate, Hypersthene. Forms: (a), (b), (m), (n), (h), (o), (c), (i), and (u).

Hypersthene

This figure exhibits a combination occurring on the ferro-magnesian meta-silicate, Hypersthene. Forms:…

The planes of this form are similar to trapeziums. Because it has twenty-four sides, it is usually called the Icositetrahedron. Its solid angles are of three kinds: six tetrahedral at the ends of the principal axes; twelve tetrahedral at the ends of the digonal axes; ans eight trihedral at the ends of the trigonal axes. There are twenty-four octahedral and twenty-four cubic edges. Naumann's symbol for this form is m0m; Dana's is m-m.

Icositetrahedron

The planes of this form are similar to trapeziums. Because it has twenty-four sides, it is usually called…

This crystal of iron-vitriol has only one plane with an absolutely fixed value, the plane of symmetry, or clinopinacoid (b).

Iron-Vitriol

This crystal of iron-vitriol has only one plane with an absolutely fixed value, the plane of symmetry,…

This image represents an isometric holohedral mirror positioned to produce a cube by reflection.

Isometric Holohedral Mirror

This image represents an isometric holohedral mirror positioned to produce a cube by reflection.

Kyanite, whose name derives from the Greek word kyanos, meaning blue, is a typically blue silicate mineral, commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Kyanite is a diagnostic mineral of the Blueschist Facies of metamorphic rocks.

Kyanite

Kyanite, whose name derives from the Greek word kyanos, meaning blue, is a typically blue silicate mineral,…

Also known as Stolzite, this crystal is bounded by the unit pyramid of the first order, P, {111} (o), and by the prism of the third order, (p).

Lead Tungstate

Also known as Stolzite, this crystal is bounded by the unit pyramid of the first order, P, {111} (o),…

Crystal; If the alternate planes of the hexoctahedron extend until the intersect, a new for will result. This form, the Pentagonal Icositetrahedron, is bounded by twenty-four similar but unsymmetrical sides. Naumann's symbol for this form is (m0n/2)r, y{lkh}; Miller's is (m0n/2)l, y{klh}; h>k>l. This form is known as 'left-handed' because it contains the left, top plane of the front, upper octant.

Lef-Handed Pentagonal Icositetrahedron

Crystal; If the alternate planes of the hexoctahedron extend until the intersect, a new for will result.…

"Isometric. Trapezohedral habit." &mdash; Ford, 1912

Leucite

"Isometric. Trapezohedral habit." — Ford, 1912