Pyrite in dolostone from the Silurian of Ohio, USA.
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6000 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals.
Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces).
Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits.
The rock shown above is a Silurian dolostone with a nice pyrite crystal-lined vug. The non-brassy coloration of most of the pyrite is due to a thin, iridescent surface tarnish that is possibly turgite (?).
Locality: Duff Quarry, Huntsville, Logan County, western Ohio, USA
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Photo gallery of pyrite:
www.mindat.org/gallery.php?min=3314
Tags: pyrite iron sulfide sulfides mineral minerals fools gold dolomite dolostone Silurian Duff Quarry Huntsville Logan County Ohio vug crystal crystals iridescent tarnish
Pyrite in dolostone from the Silurian of Ohio, USA.
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6000 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals.
Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces).
Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits.
The rock shown above is a Silurian dolostone with a nice, pyrite crystal-lined vug. The non-brassy coloration of most of the pyrite is due to a thin, iridescent surface tarnish that is possibly turgite (?).
Locality: Duff Quarry, Huntsville, Logan County, western Ohio, USA
------------------------
Photo gallery of pyrite:
www.mindat.org/gallery.php?min=3314
Tags: pyrite iron sulfide sulfides mineral minerals fools gold dolomite dolostone Silurian Duff Quarry Huntsville Logan County Ohio vug crystal crystals iridescent tarnish
Pyrite in dolostone from the Silurian of Ohio, USA.
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6000 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals.
Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces).
Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits.
The rock shown above is a Silurian dolostone with a nice, pyrite crystal-lined vug. The non-brassy coloration of most of the pyrite is due to a thin, iridescent surface tarnish that is possibly turgite (?).
Locality: Duff Quarry, Huntsville, Logan County, western Ohio, USA
------------------------
Photo gallery of pyrite:
www.mindat.org/gallery.php?min=3314
Tags: pyrite iron sulfide sulfides mineral minerals fools gold Duff Quarry Huntsville Ohio Silurian dolomite dolostone
Eurypterid - fossil sea scorpion prosoma (head) in dolostone from the Silurian of Ohio, USA.
The eurypterids, or sea scorpions, are an extinct group of chelicerate arthropods. They have an elongated, scorpion-like body that could reach enormous sizes (2.5 to 3 meters!), with a nonmineralizing exoskeleton composed of chitinous material. They are generally found in shallow to very shallow water marine and marginal marine facies.
This eurypterid head comes from Duff Quarry in western Ohio. The quarry has exposures of Silurian bedded dolostones over massive dolostones. Stromatolites and mudcracks are present, indicating shallow water to subaerial conditions. Conodont microfossils from this locality indicate a mid-Late Silurian age (= late Ludlovian to early Pridolian) (see Swift, 2011).
Classification: Animalia, Arthropoda, Chelicerata, Merostomata, Xiphosura, Eurypterida
Stratigraphy: Salina Group, upper Ludlovian Series to lower Pridolian Series, mid-Upper Silurian
Locality: Duff Quarry, north of the town of Huntsville, northern Logan County, western Ohio, USA (40° 28' 38.79" North latitude, 83° 48' 15.59" West longitude)
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Reference cited:
Swift (2011) - Conodont Biostratigraphy and δ13C Chemostratigraphy of the Salina Group (Silurian) in Western Ohio and Eastern Indiana. Master's thesis. Ohio State University, Columbus, Ohio, USA. 91 pp. (etd.ohiolink.edu/rws_etd/document/get/osu1313675443/inline)
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See info. at:
en.wikipedia.org/wiki/Eurypterus
Tags: fossil fossils sea scorpion scorpions eurypterid Eurypterida Duff Quarry Silurian Salina Group Logan County Ohio Huntsville
Pyrite in dolostone from Ohio, USA. (public display, Geology Department, Wittenberg University, Springfield, Ohio, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6000 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals.
Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces).
Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits.
The rock shown above is a Silurian dolostone with a nice, pyrite crystal-lined vug.
Locality: Duff Quarry, Huntsville, Logan County, western Ohio, USA
------------------------
Photo gallery of pyrite:
www.mindat.org/gallery.php?min=3314
Tags: pyrite mineral minerals sulfide sulfides iron fool's gold Duff Quarry Logan County Huntsville Ohio Silurian dolomite dolostone vug crystal crystals