Khawar - Answers

Pyrite or Iron pyrite (FeS2) is a very common mineral that can be found in sedimentary and low grade metamorphic rocks in the form of crystals. It is often referred to as ‘Fools Gold’ due to it’s gold-like colour. Pyrite can be found in soils and sediments throughout the Earth as myriads of microscopic crystals. This pyrite is formed by bacteria that remove oxygen from sulfate in the water, producing sulfide that reacts with iron to form pyrite. More than 90 percent of the pyrite on Earth is formed by microbiological processes. Pyrite is found in a wide variety of geological settings, from igneous, sedimentary and metamorphic rock to hydrothermal mineral deposits, as well as in coal beds and as a replacement mineral in fossils. Pyrite is a common accessory mineral in sedimentary rocks, particularly in limestone, sandstone and carbonaceous siltstones or shales. Recognized for its brass-yellow color which resembles that of gold, pyrite is a source of iron and sulfur and is used for the production of sulfuric acid. Some types of pyrite contain enough microscopic gold to warrant mining them as a gold ore. Take a magnet with you. Iron pyrite will stick to the magnet because of its high iron content; gold will not. Pyrite doesn’t melt. When heated, it gives off part of its sulphur and turns into pyrrhotite. Further heating, with plenty of air, will cause it to burn, leaving iron oxide (“rust”).

⚫Auger Mining

🔷Auger mining means a method of mining coal at a cliff or highwall by drilling holes into an exposed coal seam from the highwall and transporting the coal along an auger bit to the surface and includes all other methods of mining in which coal is extracted from beneath the overburden by mechanical devices located at the face of the cliff or highwall and extending laterally into the coal seam, such as extended depth, secondary recovery systems

As the auger rotates and advances forward, coal is cut and pushed out of the hole by the rotating action of the auger.

🔹The action is similar to that of a carpenter boring a large hole in wood using an auger bit, and that is where the name derives.

🔷Auger mining recovers around one-third of the coal under the highwall, for whatever depth of penetration is achieved.

🔹 Auger cutting heads can be as large as 7 feet in diameter and may be drilled to a depth of more than 300 feet.

When the ultimate pit limit is reached, it is difficult to “pack up and leave” when you see the exposed coal seam.

🔹 So, in some regard, the company looks at this secondary recovery technique, i.e., auger mining, as the “icing on the cake.

🔹” It amounts to coal recovery at a very low cost. It is, however, somewhat problematic and controversial.

🔷The low recovery, less than 35%, means that the majority of the reserve remains in place, but it has been sterilized, i.e., left in a condition where it will be essentially impossible for anyone to recover the remainder in the future.

🔹The holes into the side of the hill create drainage holes for acid-laden water, and that is a big problem.

What is Jade?

Jade can be described as a mineral useful as jewelry or ornaments. It is a mineral with a monoclinic crystal system. This material mostly has a green color, but it can appear in virtually all colors. It has a crystal habit of intergrown grainy or fine fibrous aggregate type. Its fracture is splintery, and it is a brittle material. The hardness can be given as 6 – 7 on the Mohs scale. Jade is a translucent material with a specific gravity of 2.9 – 3.38.

There are two forms of jade; they are nephrite jade and jadeite jade. Until 1863, it was difficult to determine whether jade was nephrite or jadeite. Nephrite contains a microcrystalline interlocking matrix with a fibrous appearance made of calcium, magnesium-iron rich amphibole minerals. It becomes more green in color when the iron content grows higher. On the other hand, jadeite is rich in sodium and aluminum pyroxene. It is the most precious type of jade and has a microcrystalline structure with an interlocking growth of crystals. This type of jade can be found only on metamorphic rocks.

There are many ornamental uses of jade in East Asia, South Asia, and Southeast Asia art. It is also a precious material in Latin America, including Mexico and Guatemala.

What is Serpentine?

Serpentine is a subgroup of kaolinite-serpentine, which has greenish, brownish, spotted minerals that exist in serpentinite rocks. This type of material is useful as a source of magnesium and asbestos. It is also useful as a decorative stone. The name serpentine comes from the green color it has, which resembles a serpent.

This subgroup of this mineral has rock-forming hydrous magnesium iron phyllosilicate minerals. These minerals are a result of the metamorphism of ultramafic rocks. Moreover, there can be some other elements, such as chromium, manganese, cobalt, and nickel. Moreover, this subgroup has polymorphous minerals, which means there is the same chemical formula with different atomic structures.

The precious or noble forms of serpentine are more attractive and durable forms, and these are useful extensively as gems and used in ornamental carvings. Furthermore, it can be easily carved, polished excellently, and has a pleasingly greasy feeling. There are, however, less valuable serpentine ores with various hardnesses and clarities that are sometimes dyed to imitate jade.