Acanthite from the Precambrian of Morocco. (9 millimeters across along the base)
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.
Acanthite (a.k.a. argentite) is a scarce silver sulfide mineral - Ag2S. On fresh surfaces, acanthite has a metallic silvery-gray appearance. On less fresh surfaces, it has a dull metallic luster and a dark gray to black-colored tarnish. Acanthite lacks cleavage, has a black streak, is fairly soft (H = 2 to 2.5), and is fairly heavy for its size. Acanthite is the most important silver ore mineral.
Geologic & age: Imiter Silver Deposit, mineralization at ~550 Ma (near-latest Neoproterozoic)
Locality: Imiter Mine, northern side of Saghro Mountain, Ouarzazate Province, Anti-Atlas Mountains, central Morocco
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Photo gallery of acanthite:
www.mindat.org/gallery.php?min=10
Tags: acanthite argentite Imiter silver deposit sulfide Neoproterozoic Proterozoic Precambrian Morocco Anti-Atlas Mountains
Acanthite from the Precambrian of Morocco. (9 millimeters across along the base)
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.
Acanthite (a.k.a. argentite) is a scarce silver sulfide mineral - Ag2S. On fresh surfaces, acanthite has a metallic silvery-gray appearance. On less fresh surfaces, it has a dull metallic luster and a dark gray to black-colored tarnish. Acanthite lacks cleavage, has a black streak, is fairly soft (H = 2 to 2.5), and is fairly heavy for its size. Acanthite is the most important silver ore mineral.
Geologic context & age: Imiter Silver Deposit, mineralization at ~550 Ma (near-latest Neoproterozoic)
Locality: Imiter Mine, northern side of Saghro Mountain, Ouarzazate Province, Anti-Atlas Mountains, central Morocco
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Photo gallery of acanthite:
www.mindat.org/gallery.php?min=10
Tags: acanthite argentite Imiter silver deposit sulfide Neoproterozoic Proterozoic Precambrian Morocco Anti-Atlas Mountains
Native silver in matrix from the Precambrian of Morocco.
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.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks and minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state as minerals.
Silver is part of the gold-group of metallic elements. Silver is a precious metal, but is far less valuable than gold or platinum. Silver usually occurs as a silver sulfide mineral, but it also occurs in nature in its native state, often in the form of twisted wires. Silver is moderately soft and has a silvery-white color on fresh surfaces that tarnishes to darker colors. Elemental silver in nature is often found alloyed with other metals. Naturally alloyed gold-silver is called electrum.
Geologic context & age: Imiter Silver Deposit, mineralization at ~550 Ma (near-latest Neoproterozoic)
Locality: Imiter Mine, northern side of Saghro Mountain, Ouarzazate Province, Anti-Atlas Mountains, central Morocco
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Photo gallery of silver:
www.mindat.org/gallery.php?min= 3664
Tags: native silver element elements mineral minerals Imiter Mine Deposit Precambrian Proterozoic Neoproterozoic Anti-Atlas Mountains
Native silver in matrix from the Precambrian of Morocco.
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.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks and minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state as minerals.
Silver is part of the gold-group of metallic elements. Silver is a precious metal, but is far less valuable than gold or platinum. Silver usually occurs as a silver sulfide mineral, but it also occurs in nature in its native state, often in the form of twisted wires. Silver is moderately soft and has a silvery-white color on fresh surfaces that tarnishes to darker colors. Elemental silver in nature is often found alloyed with other metals. Naturally alloyed gold-silver is called electrum.
Geologic context & age: Imiter Silver Deposit, mineralization at ~550 Ma (near-latest Neoproterozoic)
Locality: Imiter Mine, northern side of Saghro Mountain, Ouarzazate Province, Anti-Atlas Mountains, central Morocco
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Photo gallery of silver:
www.mindat.org/gallery.php?min= 3664
Tags: native silver element elements mineral minerals Imiter Mine Deposit Precambrian Proterozoic Neoproterozoic Anti-Atlas Mountains
Native silver in matrix from the Precambrian of Morocco.
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.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks and minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state as minerals.
Silver is part of the gold-group of metallic elements. Silver is a precious metal, but is far less valuable than gold or platinum. Silver usually occurs as a silver sulfide mineral, but it also occurs in nature in its native state, often in the form of twisted wires. Silver is moderately soft and has a silvery-white color on fresh surfaces that tarnishes to darker colors. Elemental silver in nature is often found alloyed with other metals. Naturally alloyed gold-silver is called electrum.
Geologic context & age: Imiter Silver Deposit, mineralization at ~550 Ma (near-latest Neoproterozoic)
Locality: Imiter Mine, northern side of Saghro Mountain, Ouarzazate Province, Anti-Atlas Mountains, central Morocco
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Photo gallery of silver:
www.mindat.org/gallery.php?min= 3664
Tags: native silver element elements mineral minerals Imiter Mine Deposit Precambrian Proterozoic Neoproterozoic Anti-Atlas Mountains