A Paleozoic brachiopod shell partly broken to show the internal spiral arm-supports. Mississippian limestones. Note the symmetrical character of the shell with reference to a median line drawn through the apex of beak.

Brachiopod

A Paleozoic brachiopod shell partly broken to show the internal spiral arm-supports. Mississippian limestones.…

This illustration shows calcite crystals. They are hexagonal-rhombohedral, though actual calcite rhombohedrons are rare as natural crystals.

Calcite Crystals

This illustration shows calcite crystals. They are hexagonal-rhombohedral, though actual calcite rhombohedrons…

Chara vulgaris, a modern lime-secreting alga, growing in fresh water. An important marl and limestone former.

Chara Vulgaris

Chara vulgaris, a modern lime-secreting alga, growing in fresh water. An important marl and limestone…

Chara vulgaris, a recent calcareous alga (fresh water); sport-vessel with corona. This is frequently found in great numbers in fresh-water limestones, showing their mode of origin.

Chara Vulgaris

Chara vulgaris, a recent calcareous alga (fresh water); sport-vessel with corona. This is frequently…

This Renaissance console is a Venetian design made out of Istrian limestone. It is a combination of several smaller consoles to form a composite-console.

Renaissance Console

This Renaissance console is a Venetian design made out of Istrian limestone. It is a combination of…

The chain coral. This is an important index fossil of the Silurian, and an important limestone builder as well.

Chain Coral

The chain coral. This is an important index fossil of the Silurian, and an important limestone builder…

Eolian type of cross-bedding in ancient limestones, formed of uniform lime-sand grains south of St. Louis.

Eolian Cross-bedding

Eolian type of cross-bedding in ancient limestones, formed of uniform lime-sand grains south of St.…

Eolian type of cross-bedding in ancient limestones, formed of uniform lime-sand grains south of St. Louis.

Eolian Cross-bedding

Eolian type of cross-bedding in ancient limestones, formed of uniform lime-sand grains south of St.…

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901

Laccolith

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901

A kiln or furnace in which limestone or shells are burnt to make lime.

Lime-kiln

A kiln or furnace in which limestone or shells are burnt to make lime.

Limestone polished, furrowed, and scratched by the modern glacier of Rosenlaui, Switzerland.

Limestone

Limestone polished, furrowed, and scratched by the modern glacier of Rosenlaui, Switzerland.

Granular crystallized limestone (marble) seen under crossed nicols.

Limestone

Granular crystallized limestone (marble) seen under crossed nicols.

Fragment of the wall rock (limestone) included in an ancient sandstone dike; the rock is shattered and the sand (shaded) injected into the fissures.

Limestone Fragment

Fragment of the wall rock (limestone) included in an ancient sandstone dike; the rock is shattered and…

A section of the Paleozoic rocks found in the Mississppi basin illustrating the periods and ages.

Paleozoic Rocks

A section of the Paleozoic rocks found in the Mississppi basin illustrating the periods and ages.

Pig iron is the intermediate product of smelting iron ore with coke, usually with limestone as a flux. Pig iron has a very high carbon content, typically four percent, which makes it very brittle and not useful directly as a material except for limited applications.

Pig Iron Manufacturing Apparatus

Pig iron is the intermediate product of smelting iron ore with coke, usually with limestone as a flux.…

Section to show normal progressive overlap of marine formations and their shoreward change from limestones to sandstones.

Progressive Overlap of Marine Formations

Section to show normal progressive overlap of marine formations and their shoreward change from limestones…

"Cross section of Marsh Creek valley at McCammon, Idaho." -Lee, 1915

Rock Layers Showing Types of Rock

"Cross section of Marsh Creek valley at McCammon, Idaho." -Lee, 1915

Characteristic surface features on the Santis in Switzerland produced by the solution on exposed limestone surfaces.

Santis

Characteristic surface features on the Santis in Switzerland produced by the solution on exposed limestone…

A foraminiferal shell or the Miliola type. Note that each new chamber covers all preceding ones. Important limestone builder.

A Foraminiferal Shell

A foraminiferal shell or the Miliola type. Note that each new chamber covers all preceding ones. Important…

" In Rockbridge County, Virginia, is to be found one of the greatest curiosities in the United States, a natural bridge. This bridge consists of a stupendous arch of limestone rock, over a chasm fifty feet wide dat its base and ninety feet at the top."- Lupton

Natural Bridge in Virginia

" In Rockbridge County, Virginia, is to be found one of the greatest curiosities in the United States,…

Trenton Falls, a geologist's playground, has been inspiring generations of scientists. Referred to as Kuyahoora by the natives, the leaping waters of the Deyoghtararon, was held in great spiritual regard by native peoples for centuries prior to the arrival of settlers. Trenton Falls is located in West Canada Creek Valley in north central New York State. This tributary of the Mohawk River drains much of the southwestern Adirondack Mountains. Limestone and shale dominate the rock formation at Trenton Falls.

Trenton High Falls

Trenton Falls, a geologist's playground, has been inspiring generations of scientists. Referred to as…