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Oil Shale
Oil shale is a rock that contains significant amounts of organic material in the form of kerogen. Up to 1/3 of the rock can be solid kerogen. Liquid and gaseous hydrocarbons can be extracted from oil shale, but the rock must be heated and/or treated with solvents. This is usually much less efficient than drilling rocks…
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Shale Used to Produce Clay
Everyone has contact with products made from shale. If you live in a brick house, drive on a brick road, live in a house with a tile roof, or keep plants in “terra cotta” pots, you have daily contact with items that were probably made from shale. Many years ago these same items were made…
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Uses of Shale
Some shales have special properties that make them important resources. Black shales contain organic material that sometimes breaks down to form natural gas or oil. Other shales can be crushed and mixed with water to produce clays that can be made into a variety of useful objects. Conventional Oil and Natural Gas Black organic shales…
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What is Shale?
Shale is a fine-grained sedimentary rock that forms from the compaction of silt and clay-size mineral particles that we commonly call “mud.” This composition places shale in a category of sedimentary rocks known as “mudstones.” Shale is distinguished from other mudstones because it is fissile and laminated. “Laminated” means that the rock is made up of many thin…
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Types of Sand Grains
The grains in a sandstone can be composed of mineral, rock, or organic materials. Which and in what percentage depends upon their source and how they were altered during transport. Mineral grains in sandstones are usually quartz. Sometimes the quartz content of these sands can be very high – up to 90% or more. These…
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Weathering and Transport of Sand
The grains of sand in a sandstone are usually particles of mineral, rock, or organic material that have been reduced to “sand” size by weathering and transported to their depositional site by the action of moving water, wind, or ice. Their time and distance of transport may be brief or significant, and during that journey…
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What is Sand?
To a geologist, the word “sand” in sandstone refers to the particle size of the grains in the rock, rather than the material of which it is composed. Sand-size particles range in size from 1/16 millimeter to 2 millimeters in diameter. Sandstones are rocks composed primarily of sand-size grains.
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What is Sandstone?
Sandstone is a sedimentary rock composed of sand-size grains of mineral, rock, or organic material. It also contains a cementing material that binds the sand grains together and may contain a matrix of silt- or clay-size particles that occupy the spaces between the sand grains. Sandstone is one of the most common types of sedimentary rock, and it is found in sedimentary…
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Other Materials of Quartz and Fuchsite
Other rocks are also confused with verdite. Green aventurine is a quartzite colored by flakes of fuchsite. Macrocrystalline quartz sometimes has a green color caused by abundant fuchsite inclusions. The jade minerals, jadeite and nephrite, have frequently been confused with verdite. This problem is compounded by some vendors who market verdite under the misnomer of “African jade”. Dyed quartzite and dyed chalcedony are also…
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Buddstone vs. Verdite
In nature, buddstone is often found in intimate association with verdite, and there is sometimes a gradient of one material into another. [6] People often use the names “verdite” and “buddstone” interchangeably – but there should be no confusion. The solution to this confusion is the Mohs hardness test. Buddstone (Mohs hardness of 7) is…