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What Kind Of Minerals and Crystals Can Be Found In Ohio?

Ohio Fluorite
Calcite celestite Pugh Quarry, Custar, Ohio

Calcite and celestite crystals from Ohio

If you live in Ohio and want to get rich finding Emeralds then forget it. Your best bet for that is to move to the Asheville, NC. Our state just doesn’t have the Geology necessary for that sort of gemstone to be present. It’s true people do find gold and diamonds (six of those have been found in Ohio, not including those found in jewelry stores) in Ohio, but those are travelers that arrived courtesy of glaciers and deposited in glacial sedimentary deposits.

But just because you can’t fill a jewelry shop from our geology doesn’t mean that Ohio isn’t rich in crystal treasure. Our state is blessed with minerals that are used industrially and helped turn the state into an Industrial powerhouse. It also is a source of beautiful minerals perfect for a collection or as a display piece (Celestite, I am looking at you!) And don’t get me started talking about fossils! Cincinnati is famous for its rich troves of Ordovician era fossils on the Cincinnati Arch. You know where to go if you want a Trilobite.

Since most locals aren’t aware of our state’s Geology, let alone that we have a geology, or if we have one, where somebody may have misplaced it, how much it’s worth and whether you can trade it to rent Top Gun: Maverick on Amazon, we are presenting a curated list of the crystals and minerals found in the Buckeye state.

Photo credit for image above: Photo By James St. John – https://www.flickr.com/photos/47445767@N05/33229612163/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=96284794

Calcite

Calcite crystals Gibraltar Island Lake Erie Ohio

Sunlit Silurian calcite from Put-in-Bay in Ohio on Lake Erie.

Photo By James St. John – https://www.flickr.com/photos/47445767@N05/50588186197/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=96284996

Calcite is found throughout Ohio in different forms as granular aggregates in black shale in eastern and central Ohio, and as crystal and granular aggregates in Western Ohio.

The name calcite comes from a Greek word meaning lime. This comes from its chemical component, Calcium Carbonate, which sometimes is mistakenly known as “lime.” Calcite is known in more than 300 forms of crystals. The scalenohedral crystals of Calcite, one of its most common varieties, ordinarily are known as “dogtooth spar” or “dogtooth calcite” because of their resemblance to a dog’s canine tooth. Another variety, transparent rhombohedral calcite, is used in optical equipment. Although they are not specific varieties of calcite, stalactites, stalagmites and other formations found in caverns are made of calcite.

Calcite is one of the most common minerals, making up about 4% by weight of the Earth’s crust. Calcite is common as vein fillings in many rocks in western and central Ohio. Silurian dolomites in northwestern Ohio yield clusters of large crystals ranging from clear to dark brown. Many have a golden color.

Crystals and granular aggregates in cavities and fractures of dolostones and limestones in western Ohio; granular aggregates commonly form veins in dolostone concretions and less commonly in ironstone concretions from black shales in central and eastern Ohio; more rare as an efflorescence.

Calcite (CaCO3) is a soft carbonate mineral that occurs in various colors, including white, yellow, brown, gray, black, and pink, and also can be colorless. Calcite is a common mineral that occurs primarily in limestone and dolostone, occasionally in concretions and rarely as an efflorescence.

The Romans made concrete by mixing lime and volcanic ash to create a pozzolanic reaction. If this was mixed with volcanic tuff and placed under seawater, the seawater hydrated the lime in an exothermic reaction that solidified the mixture.

Aragonite

vug with aragonite east central ohio

Vug with aragonite crystals in arenaceous, ferruginous, fossiliferous limestone from Ohio

Photo By James St. John – Vug with aragonite crystals in arenaceous, ferruginous, fossiliferous limestone (Vinton Member, Logan Formation, Lower Mississippian; Mt. Calvary Cemetery Outcrop – Rt. 13 roadcut, Heath, east-central Ohio, USA) 3, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=82971990

With a name that sounds like a heroic character in J.R.R. Tolkien’s The Lord of the Rings, but originates from the territory of Aragon in Spain, aragonite is one of the three most common forms of calcium carbonate. Its crystal lattice differs from calcite, one of the other common forms of calcium carbonate. It has a host of industrial uses. Aragonite has been found in Coshocton County.

Celestite

Celestite Crystals inside Crystal Cave on South Bass Island

Crystal Cave is a small cave in Put-in-Bay on Lake Erie in Ohio touted as the world’s largest geode. An abundance of large, well-formed crystals of celestite cover the walls. The cave was originally mined for its strontium content, but enough nice crystals still remain to keep the site open as a show cave.

Photo by James St. John – Celestite (Crystal Cave, South Bass Island, Lake Erie, Ohio, USA) 16, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=82969277

A soft sulfate mineral ore of strontium, in fact being the most common mineral that contains strontium. Celestite derived strontium is used industrially in fireworks, ceramic magnets, and toothpaste

Ohio is famous for having some of the best celestite deposits in the world. The mineral is found in 11 counties. The northwestern regions of Ohio amid the Findlay Arch produce celestite ranging in color from white to pale blue. The area of Serpent Mound southwestern Ohio also produces some celestite due to an unusual geological occurrence. South Bass Island is a huge vug filled with very large celestite crystals.

Quartz

Geode with sphalerite barite dolomite and quartz Monroe County Ohio

Close-up of a Monroe County, Ohio geode with sphalerite, barite, dolomite and quartz.

Photo by James St. John – Geode with sphalerite, barite, dolomite, and quartz (Monroe County, Ohio, USA) 2, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=84692026

What can’t you not say about quartz? It is a hard silicate in the form of silicon dioxide. It’s useful in glassmaking, watchmaking, ceramics, metal casting, electronics, and the petroleum industry. But the enduring love it receives is because of it’s beauty and variety: rose quartz, lavender quartz, blue quartz, rutilated quartz, citrine, amethyst, enhydro quartz, prasiolite, ametrine and a variety of shapes including points, needles, and clusters.

In Ohio, quartz is found in flint beds in Coshocton, Licking, and Muskingum Counties; in Adams and Highland Counties; in septarian limestone concretions in the central portion of the state; and loose in streambeds and creeks in the Southeast.

Fluorite

Ohio Fluorite

An example of Ohio Fluorite from Stoneco Auglaize quarry (Maumee Stone County quarry), Junction, Paulding County, Ohio.

A 1.2 cm colorless cube with well-centered, distinct, rich purple color “phantom” inside. The crystal has very sharp faces and excellent gemminess. It sits upon a small amount of Dolostone matrix

Photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10148353

Fluorite is a another name for calcium fluoride, a halide ore mineral of fluorine. It’s has several industrials uses including as a flux for removing impurities in the manufacture of steel and in the production of fluorine gas which itself is used in the refining of uranium.

While fluorite is found across the world, the quality and largest quantities are mined out of Europe and North America. In Ohio fluorite is found in 19 counties. Typically cubic crystals found in dolostones in northwestern Ohio particularly along the edges of the Findlay Arch and occasionally in the Serpent Mound area.

Some fluorite is UV reactive, fluorescing under exposure. Because of this property, it and it’s compounds are used to manufacture synthetic crystals with applications in laser and special UV and infrared optics.

Dolomite

Put-in-Bay Dolomite South Bass Island, Lake Erie,Ohio

Ohio Dolostone. In the past Dolomite was used to refer to both the mineral and the rock. Dolomite is now used to refer to the mineral and dolostone refers to sedimentary rock whose primary content is dolomite.

Photo By James St. John – Put-in-Bay Dolomite over Tymochtee Dolomite (Upper Silurian; South Bass Island, Lake Erie, Ohio, USA) 6, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=82969360

What relationship does Ohio have with a nineteenth century french geologist? The answer in one word is Dolomite! Named after Déodat Gratet de Dolomieu, Dolomite is found in over 19 Ohio counties. Dolomite differs from limestone in that it contains both calcium and magnesium.

More well known as an Indiana mineral, especially the Corydon area, this calcium magnesium carbonate occurs in small crystals in western Ohio and along the Huron river among other areas.

Dolomite has industrial uses including as a source of magnesium salts like magnesia and by builders as structural and ornamental stone.

The term dolomite used to refer both to the mineral dolomite and dolostone (a sedimentary rock of which is made primarily of dolomite).

Barite

Fluorite and barite (quarry in Marblehead Peninsula, far-northern Ohio

Fluorite and barite from Marblehead Peninsula Ohio

Photo By James St. John – Fluorite and barite (quarry in Marblehead Peninsula, far-northern Ohio, USA), CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=40022633

Found in over 26 counties in Ohio, this Barium Sulfate mineral often associated with calcite and other minerals is often white or colorless but can also have light blues, greys, yellows or browns. In the central and eastern Ohio black shale formations barite is found in concretions such as limestone, ironstone and pyrite. In the northwestern and southwestern Ohio crystalline or granular barite can be found in fractures and cavitiesof dolostones (dolomite sedimentary rock).

Barite is the primary ore for barium, and has varied industrial uses including paper, paint and glass manufacture as well medical radiology (as a dye) and in oil drilling.

Barites crystals found in Ohio can sometimes be massive in size.

Malachite

Malachite,Zaire

Malachite – sadly from Zaire and not Ohio

Photo By JJ Harrison (https://www.jjharrison.com.au/) – Own work, CC BY-SA 3.0,https://commons.wikimedia.org/w/index.php?curid=7515677

Typically found in botryoidal, stalagmitic, or fibrous masses, beautiful green malachite is collectible, and displayable.

It was a little hard to believe that malachite is found in Ohio, but according to the state it actually is present. Since it’s a copper carbonate hydroxide mineral it obviously needs copper to be present to form, and I did find a reference to a copper mine in Cuyahoga county.

Pyrite

Pyrite snake concretion Ohio Shale Upper Devonian creek cut in Ross County, southern Ohio, USA

Pyrite

Photo By James St. John – Pyrite snake concretion (Ohio Shale, Upper Devonian; creek cut in Ross County, southern Ohio, USA) 8, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=84692435

Iron Pyrite, commonly known as “fool’s gold”, is metallic iron sulfide mineral found in over 88 Ohio counties, typically in Devonian or Pennsylvanian shales. Pyrite has been used as an ore for sulfur and a source of iron.

The most common sulfide mineral, pyrite can form form in extremely well-crystallized examples of cubes, pyritohedrons, and octahedrons.

Sphalerite

Sphalerite on dolostone Millersville Quarry, Sandusky County, Ohio

Sphalerite crystals atop sucrosic dolostone from Sandusky County, Ohio

Photo by James St. John – https://www.flickr.com/photos/jsjgeology/31282767801/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=101721070

Sphalerite is a sulfide mineral that is an ore of zinc, cadmium, gallium, germanium, and indium. It has a wide variety of colors including light/dark brown, red-brown, yellow, red, green, light blue, black, and colorless. It occurs in the Findlay Arch area, near Serpent Mound, and in Eastern Ohio.

Smithsonite

example of smithsonite

Illustrative example of smithsonite – sadly, not from Ohio. This example is from the Kelley Mine in Soccorro County, New Mexico.

Photo by Bureau of Mines – http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20BOM%20Mineral%20Specimens%20016, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1825549

Smithsonite is named after English geologist and chemist James Smithson. Also known as zinc spar, this form of mineral zinc carbonate is a variably colored trigonal mineral.

Special Mention: Fossils

While not minerals, it would be unforgivable to not mention Ohio’s rich treasure trove of minerals. The greater Cincinnati area (which includes parts of northern Kentucky and southeastern Indiana) sits atop what is known as the Cincinnati Arch, the eroded remains of a mountain range from Michigan to Alabama that was thrust up by collision of two ancient continents. The arch sank beneath a series of shallow inland seas filled with marine life ending up as deposits of fossils in what is known to geologists as the Cincinnatian Epoch.

The region is famous for a wide variety of marine fossils, but particularly Trilobites, a now extinct member of the arthropod family.

Phacops rana,Silica,Ohio

Example of Ohio Eldredgeops rana fossil

Photo by Daderot – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=83993913

Graftonoceras – limonite-stained external mold of nautiloid in dolostone

Photo By James St. John – Graftonoceras fossil nautiloid (Lockport Dolomite, Middle Silurian; Coldwater, southern Mercer County, western Ohio, USA), CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=36833417

Graftonoceras fossil nautiloid (Lockport Dolomite, Middle Silurian;Coldwater,southern Mercer County).
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This Week’s Mineral Spotlight: Gorgeous Green Malachite

Malachite from Zaire

If the mineral is green and gorgeous there is a good chance it’s malachite. Like its copper cousins Turquoise, Azurite, and Chrysocolla, Malachite is found in copper deposits. It first became useful to humans as an ore used by the ancients to produce copper metal. Today, its primary use is decorative: bracelets, necklaces, pendants, as a gemstone and cabochon, and other types of jewelry. It’s also popular as a tumbled stone and as a standout display specimen for rock and mineral collections.

North American deposits include Mexican deposits in Milpillas; American deposits in Bisbee, Morenci, Bingham Canyon and others; African deposits in Namibia, Gabon, Zambia, Uganda, and The Democratic Republic of Congo (Zaire). Russia was at a one a major source of Malachite, particularly gem quality stones, however most of these deposits have been mined out and eclipsed by the quantity and quality of the African deposits. African mines product spectacular massive malachite specimens as well as gem quality malachite, and plancheite, cuprite and carrollite are also present in these deposits.

Malachite from a Smelter's Crucible

Malachite from a Smelter’s Crucible, Egyptian, Joint reign of Hatshepsut and Thutmose III, ca. 1479–1458 B.C., 18th Dynasty

Copper deposit don’t typically yield huge amounts of malachite. Previously, Russia was the only significant source of a large volume of gem-grade malachite, but as the Russian mines have declined and the African mines became available the African finds have far exceeded Russian production. African banded layers malachite is sometimes over a foot thick with very tightly packed submicroscopic needle crystals. Since the opening of the African mines, the mineral market has great cutting-grade malachite with bands of very light green to almost black- green.

Malachite was well known to the ancients.  It’s Latin name, “Molchitis” derives from the Greek “molochites lithos” whose meaning is “mallow green stone” due to the mineral’s resemblance to the mallow plant’s leaves.  Some evidence exists o Malachite mining in Britain at the Great Orme Mines perhaps as far back as the 3rd and 4th millenia B.C. There is also archaeological evidence of Malachite mining and smelting to produce copper 3,000 years ago in the Timna Valley, associated with King Solomon’s Mines in modern day Israel, where it is still mined to today to produce copper. 

Lapidary, work with malachite requires a facemask. The copper carbonate dust from Malachite is poisonous. Most lapidaries use water to cut down on the dust in the air. Undercutting is often a problem during polishing, since each malachite band has a slightly different Mohs hardness, however experienced lapidaries shouldn’t have a problem. Banded malachite is always beautiful no matter how it is used.

Qing Chinese Malachite Carving, Late 18th – Early 19th Century. Seated Luohan With Servant

Above is an outstanding example of carved malachite. A Qing era Chinese art work originating in the late 19th through early 20th century, it depicts a seated luohan, or one who has achieved enlightenment. This particular luohan is identified as Nakula who sits in meditation with a rosary; a boy-servant attends at his feet. From his long eyebrows and position beneath a tree. Carved writing in the upper right corner is a poem of praise for Nakula in the upper right was authored by the Jiaqing emperor (r. 1796–1820) and inscribed in the hand of his elder brother Yongxing (1752–1823).

Malachite Monumental Vase

French Monumental Malachite Vase. Lapidary Work Early 19th Century, Pedestal And Mounts By Pierre Phillippe Thomire

The monumental vase above is crafted from Russian malachite, bronze, gilt bronze and a filling material. Malachite grows in layers of tiny crystals its colors correlating with different crystal sizes, creating the pattern. During the late eighteenth and nineteenth centuries, most malachite came from Russian mines by the noble Demidov family. The family exploited hardstone quarries and metal deposits located on their estates in the remote Ural Mountains. In the 1820s on of the great discoveries in the history of semiprecious stones happened when an enormous malachite boulder around five hundred tons was unearthed there. Malachite is extremely brittle, so only small display objects can be cut from single blocks of the material. Large objects require a core structure, to which the malachite can be attached in thin pieces, effectively a veneer. Russian craftsmen developed a method to use the stone’s natural pattern and a precision cutting technique to form a continuing or “endless” ornamentation. This type of veneering appears nearly seemless and is called “Russian mosaic”.

The Demidov family used the flashy appearance of malachite to improve their social status, filling their palaces with the material and even decorating an entire room with the green stone, which inspired Czar Nicolas I to commission the famous Malachite Room in the Czar’s Winter Palace in Saint Petersburg.

The monumental vase above is modeled on an ancient Roman bell-shaped krater, the most famous example of which is the first-century Medici Vase, now in the Galleria degli Uffizi, Florence. This shape was quite much admired through the early nineteenth century. Count Nikolai Demidov commissioned this particular malachite vase for his villa at San Donato, near Florence. Unlike with the Russian mosaic technique, large areas of this vase’s surface is composed of small malachite particles mixed with filling substance in the same way as modern terrazzo. This raw malachite was probably transported from one of his mines to Florence to be shaped and finished by local artists not trained in the specialized Russian technique. The vase would then have been sent onwards to Paris to be fitted with its mounts and pedestal.

The gilded bronze winged female figures on the body of the vase represent Fame. Their trumpets are shaped like handles, although the vase is too heavy to be lifted like a loving cup. A gilded bronze laurel garland of laurel (Laurus nobilis) runs under the lip mount. The laurel had been adopted by Lorenzo de’ Medici (who was also a lavish patron of the arts) as an emblem of his house with the motto “Ita ut virtus,” or “Thus is virtue”— that is to say, virtue is evergreen. It’s use here implies that the Demidov’s hoped that their fortune would also be evergreen.

The mounts and bronze pedestal were made by Pierre-Philippe Thomire (1751–1843), known throughout Europe for his bronze decorations and ornamental sculpture. He established a reputation before the French Revolution with beautiful mounts for Sèvres porcelain vases. In 1804 he founded a workshop that produced furniture as well as luxury bronzes.

Malachite and Azurite

Malachite with Azurite

Malachite Thumbnail

PropertyDescription of Malachite
Chemical Composition:Cu2(CO3)(OH)2
Mohs Hardness:3.5 to 4.0
Specific Gravity:3.6 to 4.0
Crystal System:Monclinic
Cleavage:Perfect in one direction, fair in a second direction
Diaphaneity:Most examples are opaque while crystals are translucent
Luster:Polishes to a very bright luster. Large specimens tend to be dull and earthy. Silky luster in fibrous examples. Unusual crystals trend from vitreous to adamantine.

Even though chyrsocolla and azurite are both copper based minerals, malachite is a better indicator of the presence of significant copper deposits. The Copper Queen mine in Brisbee was created on the basis of malachite deposits.

Malachite Copper Crescent Zaire Congo

Malachite Copper Crescent from Zaire (Democratic Republic of Congo)

Malachite Under a Stereoscopic Microscope

Image of Malachite Taken Under a Stereoscopic Microscope

Malachite has a number of different cultural meanings and associations. For the Chinese, Malachite is a lucky stone for those born in the Year of the Rabbit or Year of the Tiger. For the ancient Egyptians, the color green was associated with death and the power of resurrection – as well as new life and fertility. They believed that the afterlife contained the “Field of Malachite”, an eternal paradise resembling their lives but with no pain or suffering. They also used the material in powder form for cosmetics, particularly to try to resemble Horus, the falcon headed god Those who believe in crystal healing, crystal spirituality believe the stone has any number of healing, or metaphysical properties on the body, spirit or chakra.

View our collection of beautiful malachite specimens for sale, perfect as display piece on your table or mantle, for your collection, or for use in spiritual or crystal healing.

Learn more about Malachite at Mindat.

First image by JJ Harrison (https://www.jjharrison.com.au/) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7515677 .

Fifth image by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10148274.

Sixth image by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10130475.dex.php?curid=10148274.

Seventh image by Karolina Fok – Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=84931097.rg/w/index.php?curid=10148274.