The Radiate, Acaleph; a Medusa from the genus Tiaropsis.

Acaleph Radiate

The Radiate, Acaleph; a Medusa from the genus Tiaropsis.

"Triclinic. Usually in tabular crystals parallel to brachypinacoid." — Ford, 1912

Albite

"Triclinic. Usually in tabular crystals parallel to brachypinacoid." — Ford, 1912

"Triclinic. Sometimes elongated parallel to b crystal axis." — Ford, 1912

Albite

"Triclinic. Sometimes elongated parallel to b crystal axis." — Ford, 1912

"Triclinic. Twinning very common, according to the albite law and evidenced by fine striation lines on the better cleavage surface." — Ford, 1912

Albite

"Triclinic. Twinning very common, according to the albite law and evidenced by fine striation lines…

Diagram of alluvial cones, showing surface and underground structures.

Alluvial Cones

Diagram of alluvial cones, showing surface and underground structures.

Diagram showing the progressive overlapping of the successive divisions of an alluvial fan, away from the source of supply.

Alluvial Fan

Diagram showing the progressive overlapping of the successive divisions of an alluvial fan, away from…

The Amazon River is the largest, most voluminous river on earth, having a greater total flow than the next six largest rivers combined.

Amazon River

The Amazon River is the largest, most voluminous river on earth, having a greater total flow than the…

A mollusk radiate from the Paleozoic time, Ambonychia bellistriata.

Ambonychia Mollusk

A mollusk radiate from the Paleozoic time, Ambonychia bellistriata.

Amphibole.

Amphibole

Amphibole.

Amphibole.

Amphinole

Amphibole.

"Monoclinic. Crystals prismatic in habit; the prism faces make angles of 55 and 125 degrees with each other." — Ford, 1912

Amphibole

"Monoclinic. Crystals prismatic in habit; the prism faces make angles of 55 and 125 degrees with each…

"Monoclinic. Crystals prismatic in habit; the prism faces make angles of 55 and 125 degrees with each other." — Ford, 1912"

Amphibole

"Monoclinic. Crystals prismatic in habit; the prism faces make angles of 55 and 125 degrees with each…

"Andalusite is an aluminum silicate...found in imbedded crystals in clay slate." -Dana, 1883

Andalusite

"Andalusite is an aluminum silicate...found in imbedded crystals in clay slate." -Dana, 1883

Anglesite.

Anglesite

Anglesite.

Paradoxides was a genus of relatively large trilobites, extinct marine arthropods, that form the class Trilobita found throughout the world during the Mid Cambrian period (540 million years ago). It was a moderately large trilobite with a semicircular head, free cheeks each ending with a long, narrow, recurved spine, and relatively large eyes. Its elongated trunk was composed of 20 segments and again was adorned with longish, recurved lateral spines. Its pygidium(caudal shield) was comparatively small and had one or two pairs of long spines on the posterior margin.

Paradoxides Harlani

Paradoxides was a genus of relatively large trilobites, extinct marine arthropods, that form the class…

"A complex crystal of apatite with the faces of a third-order pyramid upon it." — Ford, 1912

Apatite

"A complex crystal of apatite with the faces of a third-order pyramid upon it." — Ford, 1912

"Hexagonal; tri-pyramidal. Crystals usually long prismatic in habit; sometimes short prismatic or tabular. Usually terminated by prominent pyramid of first order and frequently a basal plane." — Ford, 1912

Apatite

"Hexagonal; tri-pyramidal. Crystals usually long prismatic in habit; sometimes short prismatic or tabular.…

"Hexagonal; tri-pyramidal. Crystals usually long prismatic in habit; sometimes short prismatic or tabular. Usually terminated by prominent pyramid of first order and frequently a basal plane." — Ford, 1912

Apatite

"Hexagonal; tri-pyramidal. Crystals usually long prismatic in habit; sometimes short prismatic or tabular.…

Apophyllite.

Apophyllite

Apophyllite.

Apophyllite.

Apophyllite

Apophyllite.

"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."…

"Generalized schematic of the hydrogeology of the study area. 1, unconfined conditions (Hawthorn Formation absent or very thin); 2, semiconfined conditions (Hawthorn Formation less than 100 feet thick); 3, confined conditions (Hawthorn Formation greater than 100 feet thick)." -Hatzell, 1995

Upper Floridan Aquifer

"Generalized schematic of the hydrogeology of the study area. 1, unconfined conditions (Hawthorn Formation…

"Orthorhombic. Acicular pyramidal; consisting of a prism terminated by a combination of a very steep pyramid and brachydome." — Ford, 1912

Aragonite

"Orthorhombic. Acicular pyramidal; consisting of a prism terminated by a combination of a very steep…

"Orthorhombic. Tabular; consisting of prominent brachypinacoid faces modified by a prism and a low brachydome." — Ford, 1912

Aragonite

"Orthorhombic. Tabular; consisting of prominent brachypinacoid faces modified by a prism and a low brachydome."…

"Orthohombric. Usually in tabular diamond-shaped crystals, formed by a short prism terminated by low brachydomes. The brachydomes are usually striated parallel to the brachy-axis." — Ford, 1912

Arsenopyrite

"Orthohombric. Usually in tabular diamond-shaped crystals, formed by a short prism terminated by low…

Artesian Wells differ from ordinary wells in that their waters are discharged by natural pressures on their reservoirs, so that pumping is not necessary to raise the water Such wells are therefore true springs.

Artesian Well

Artesian Wells differ from ordinary wells in that their waters are discharged by natural pressures on…

An articulate radiate from the Paleozoic time, Homalonotus delphinocephalus.

Articulate Radiate

An articulate radiate from the Paleozoic time, Homalonotus delphinocephalus.

An articulate radiate from the Paleozoic time, Orthoceras junceum.

Orthoceras Articulate

An articulate radiate from the Paleozoic time, Orthoceras junceum.

An ancient articulate from the Paleozoic time, Pacops bufo from the Hamilton group.

Pacops Articulate

An ancient articulate from the Paleozoic time, Pacops bufo from the Hamilton group.

"Diagram illustrating Darwin's theory of the formation of Atolls." -Geikie, 1893

Atoll Formation

"Diagram illustrating Darwin's theory of the formation of Atolls." -Geikie, 1893

"Atolls. A coral island commonly consists of a narrow rim of reef, surrounding a lagoon." -Dana, 1880

Coral Island of Atoll

"Atolls. A coral island commonly consists of a narrow rim of reef, surrounding a lagoon." -Dana, 1880

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o to a, there is shallow water for some distance out; and where not too deep, the bottom is covered here and there with growing corals. Between a and b there is a platform of coral rock, mostly bare at low tide, but covered at high ... b to d is the wooded portion of the island. The whole width (is) from the beach (b) to the lagoon (c)." -Dana, 1880

Section of Coral Island of an Atoll

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o…

Australia's 7,686,850 square kilometers landmass is on the Indo-Australian Plate. Surrounded by Indian, Southern and Pacific oceans, Australia is separated from Asia by the Arafura and Timor seas. Australia has a total 25,760 kilometers of coastline.

Australian Scenery

Australia's 7,686,850 square kilometers landmass is on the Indo-Australian Plate. Surrounded by Indian,…

Axinite.

Axinite

Axinite.

"Triclinic. Crystals usually thin with sharp edges but varied in habit." — Ford, 1912

Axinite

"Triclinic. Crystals usually thin with sharp edges but varied in habit." — Ford, 1912

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through its center, and a similar point is found on the line at an equal distance beyond the center." — Ford, 1912

Symmetry axis

"A crystal has a center of symmetry if an imaginary line is passed from some point on its surface through…

Barite.

Barite

Barite.

"Orthohombic. Crystals usually tabular parallel to base; often diamond shaped because of the presence of a short prism. Both macro- and brachydomes usually present, either beveling the corners of the diamond-shaped crystals, or if the prism faces are wanting, beveling the edges of the tavles and forming rectangular prismatic-shaped crystals elongated parallel to either the brachy- or macro-axis." — Ford, 1912

Barite

"Orthohombic. Crystals usually tabular parallel to base; often diamond shaped because of the presence…

"Orthohombic. Crystals usually tabular parallel to base; often diamond shaped because of the presence of a short prism. Both macro- and brachydomes usually present, either beveling the corners of the diamond-shaped crystals, or if the prism faces are wanting, beveling the edges of the tavles and forming rectangular prismatic-shaped crystals elongated parallel to either the brachy- or macro-axis." — Ford, 1912

Barite

"Orthohombic. Crystals usually tabular parallel to base; often diamond shaped because of the presence…

"Columnar structure in the basalt of the main sheet, south end of East Hill Cliff, near South Britain, Connecticut." -Walcott, 1901

Basalt

"Columnar structure in the basalt of the main sheet, south end of East Hill Cliff, near South Britain,…

"Diagram to illustrate the inferred structure in the vicinity of the "Triangle." Arkose conglomerate is represented by lines and ellipses, anterior basalt by the black areas, anterior shale by parallel lines, and main basalt by cross-hachure areas. The finer hachuring (and hence the deeper shade) corresponds to the higher blocks of the basalt." -Walcott, 1901

Basalt Diagram

"Diagram to illustrate the inferred structure in the vicinity of the "Triangle." Arkose conglomerate…

Basaltic columns in Wales.

Basaltic Columns

Basaltic columns in Wales.

"Basaltic rock interstratified with aqueous rocks; b Basaltic dyke." -Taylor, 1904

Basaltic Rock

"Basaltic rock interstratified with aqueous rocks; b Basaltic dyke." -Taylor, 1904

"Idealized profile to show the supposed structure in the rampart slope of the basin to the west of Ragland." -Walcott, 1901

Basin

"Idealized profile to show the supposed structure in the rampart slope of the basin to the west of Ragland."…

General view, in part schematic, of the "Bassin du Puy" and the "Chaine du Velay" or "Chaine du Deves," Central France.

Bassin du Puy

General view, in part schematic, of the "Bassin du Puy" and the "Chaine du Velay" or "Chaine du Deves,"…

"Section of a beach defined by High- and Low-water Mark." -Geikie, 1893

Beach Section

"Section of a beach defined by High- and Low-water Mark." -Geikie, 1893

"Bear Butte, from the North." -Walcott, 1901

Bear Butte

"Bear Butte, from the North." -Walcott, 1901

"Hexagonal. Strong prismatic habit. Frequently vertically striated and grooved. Forms usually present consist only of prism of first order and base." — Ford, 1912

Beryl

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

"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…

Beryl is a mineral containing beryllium and aluminum in the form of a silicate.

Crystal of Beryl

Beryl is a mineral containing beryllium and aluminum in the form of a silicate.

"Orthohombric. Crystals usually short prismatic to tabular. Sometimes quite complex with many prism, pyramid and dome faces. Frequently twinned, giving tabular crystals with recurring reentrant angles in the prism zone." — Ford, 1912

Bournonite

"Orthohombric. Crystals usually short prismatic to tabular. Sometimes quite complex with many prism,…

The shell of the brachiopod, Lingula Lewisii.

Brachiopod

The shell of the brachiopod, Lingula Lewisii.

The shell of Athyris concentrica, a species of brachiopod.

Athyris Brachiopod

The shell of Athyris concentrica, a species of brachiopod.

The dorsal valve of the brachiopod Atrypa reticularis.

Atrypa Brachiopod

The dorsal valve of the brachiopod Atrypa reticularis.

The shell of Atrypa reticularis, a species of brachiopod.

Atrypa Brachiopod

The shell of Atrypa reticularis, a species of brachiopod.

A mollusk radiate from the Paleozoic time, Pentamerus oblongus, a brachiopod from the Clinton group.

Pentamerus Brachiopod

A mollusk radiate from the Paleozoic time, Pentamerus oblongus, a brachiopod from the Clinton group.

The shell of Spirifer striatus, a species of brachiopod.

Spirifer Brachiopod

The shell of Spirifer striatus, a species of brachiopod.

Interior of the dorsal valve of Spirifer striatus.

Spirifer Brachiopod

Interior of the dorsal valve of Spirifer striatus.

The interior view of the brachiopod Waldheimia flavescens.

Waldheimia Brachiopod

The interior view of the brachiopod Waldheimia flavescens.

Brookite.

Brookite

Brookite.