Kimberlite, an igneous rock and a rare variant of peridotite, is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat diamond called the Star of South Africa in 1869 spawned a diamond rush and led to the excavation of the open-pit mine called the Big Hole. Previously, the term kimberlite has been applied to olivine lamproites as Kimberlite II, however this has been in error.
Ilmenite is a titanium-iron oxide mineral with the idealized formula FeTiO
3. It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics.
Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the cerium-dominant member of the group. It occurs usually in small isolated crystals. It has a hardness of 5.0 to 5.5 on the Mohs scale of mineral hardness and is relatively dense, about 4.6 to 5.7 g/cm3. There are five different most common species of monazite, depending on the relative amounts of the rare earth elements in the mineral:
Placer mining is the mining of stream bed deposits for minerals. This may be done by open-pit mining or by various surface excavating equipment or tunneling equipment.
Black sand is sand that is black in color. One type of black sand is a heavy, glossy, partly magnetic mixture of usually fine sands containing minerals such as magnetite, found as part of a placer deposit. Another type of black sand, found on beaches near a volcano, consists of tiny fragments of basalt.
Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.
Heavy mineral sands are a class of ore deposit which is an important source of zirconium, titanium, thorium, tungsten, rare-earth elements, the industrial minerals diamond, sapphire, garnet, and occasionally precious metals or gemstones.
Ironsand, also known as iron-sand or iron sand, is a type of sand with heavy concentrations of iron. It is typically dark grey or blackish in color.
Kenmare Resources plc is a publicly traded mining company headquartered in Dublin, Republic of Ireland. Its primary listing is on the London Stock Exchange and it has a secondary listing on Euronext Dublin. Kenmare is one of the world's largest mineral sands producers and the Company owns and operates the Moma Titanium Minerals Mine. Moma is one of the world's largest titanium minerals deposits, located 160 km from the city of Nampula in Mozambique.
Mining in the Gambia, which is limited to the production of clay, laterite, sand and gravel, silica sand, and zircon, does not play a significant role in the Gambian economy.
Huttonite is a thorium nesosilicate mineral with the chemical formula ThSiO4 and which crystallizes in the monoclinic system. It is dimorphous with tetragonal thorite, and isostructual with monazite. An uncommon mineral, huttonite forms transparent or translucent cream–colored crystals. It was first identified in samples of beach sands from the West Coast region of New Zealand by the mineralogist Colin Osborne Hutton (1910–1971). Owing to its rarity, huttonite is not an industrially useful mineral.
IREL (India) Limited is an Indian Public Sector Undertaking based in Mumbai, Maharashtra. It specializes in mining and refining rare earth metals.
The geology of Egypt includes rocks from Archaean - early Proterozoic times onwards. These oldest rocks are found as inliers in Egypt’s Western Desert. In contrast, the rocks of the Eastern Desert are largely late Proterozoic in age. Throughout the country this older basement is overlain by Palaeozoic sedimentary rocks. Cretaceous rocks occur commonly whilst sediments indicative of repeated marine transgression and regression are characteristic of the Cenozoic Era.
The mining industry of Madagascar is mostly on a small scale, centred mainly around remote locations with large mineral deposits. Mining potential is noted in industrial and metallic minerals, energy, precious and semi-precious stones, as well as ornamental stone. The mining sector was neglected by the government for decades prior to the mid-2000s. In 2013, the mining industry, a main source of foreign investment, was struggling due to "low metals prices and distrustful companies", attributed to a 2009 coup.
The mining industry of Liberia has witnessed a revival after the civil war which ended in 2003. Gold, diamonds, and iron ore form the core minerals of the mining sector with a new Mineral Development Policy and Mining Code being put in place to attract foreign investments. In 2013, the mineral sector accounted for 11% of GDP in the country and the World Bank projected a further increase in the sector by 2017.
The geology of the Gambia is defined by thick and comparatively recent sequences of sediments and sedimentary rocks, deposited in the last 66 million years. The country is underlain almost entirely by geologically recent Cenozoic sedimentary rocks. Much deeper basement rocks are likely present, although they are not well understood. Most research has focused on oil and groundwater exploration.
The geology of Ghana is primarily very ancient crystalline basement rock, volcanic belts and sedimentary basins, affected by periods of igneous activity and two major orogeny mountain building events. Aside from modern sediments and some rocks formed within the past 541 million years of the Phanerozoic Eon, along the coast, many of the rocks in Ghana formed close to one billion years ago or older leading to five different types of gold deposit formation, which gave the region its former name Gold Coast.
The Siilinjärvi carbonatite complex is located in central Finland close to the city of Kuopio. It is named after the nearby town of Siilinjärvi, located approximately 5 km west of the southern extension of the complex. Siilinjärvi is the second largest carbonatite complex in Finland after the Sokli formation, and one of the oldest carbonatites on Earth at 2610±4 Ma. The carbonatite complex consists of a roughly 16 km long steeply dipping lenticular body surrounded by granite gneiss. The maximum width of the body is 1.5 km and the surface area is 14.7 km2. The complex was discovered in 1950 by the Geological Survey of Finland with help of local mineral collectors. The exploration drilling began in 1958 by Lohjan Kalkkitehdas Oy. Typpi Oy continued drilling between years 1964 and 1967, and Apatiitti Oy drilled from 1967 to 1968. After the drillings, the laboratory and pilot plant work were made. The mine was opened by Kemira Oyj in 1979 as an open pit. The operation was sold to Yara in 2007.
The Rock Flat Placer is a small placer deposit in central Idaho which is part of the Meadows Mining District. It is known to produce gold, corundum, garnet, zircon, monazite, chromite, ilmenite, magnetite, platinum, topaz, and spinel. Additionally, it is known to produce the occasional diamond, but the last one found was in the 1920s.
The Barrytown Flats are a 17 km (11 mi) coastal plain north of Greymouth on the West Coast of New Zealand's South Island. A series of postglacial shorelines and dunes backed by a former sea cliff, they was originally covered with wetland and lowland forest, including numerous nīkau palms. The sands were extensively sluiced and dredged for gold from the 1860s, centred on the small settlement of Barrytown. The drier areas of the flats have been converted into pasture, but significant areas of forest remain, including Nikau Scenic Reserve. The flats are bordered by Paparoa National Park and the only breeding site of the Westland petrel. There are significant deposits of ilmenite in the Barrytown sands, and there have been several mining proposals, but the possible environmental consequences have been contentious.
