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Rutile Mining
Heavy mineral sands are mined in the shallow marine environment by ships that dredge up sediments, separate out the heavy mineral grains, retain the heavy minerals on-board, and discharge the lighter sediment fraction back to the bottom. Heavy mineral sands are also found on land in sedimentary deposits that accumulated at times when sea level…
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Geologic Occurrence of Rutile
Rutile occurs as an accessory mineral in plutonic igneous rocks such as granite and in deep-source igneous rocks such as peridotite and lamproite. In metamorphic rocks, rutile is a common accessory mineral in gneiss, schist and eclogite. Well-formed crystals of rutile are sometimes found in pegmatite and skarn. Rutile and a number of other metallic ore minerals are mined together from sedimentary deposits known as…
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What is Rutile?
Rutile is a titanium oxide mineral with a chemical composition of TiO2. It is found in igneous, metamorphic and sedimentary rocks throughout the world. Rutile also occurs as needle-shaped crystals in other minerals. Rutile has a high specific gravity and is often concentrated by stream and wave action in “heavy mineral sands” that exist today in both onshore and offshore deposits. Much of the…
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Ilmenite on the Moon
Apollo astronauts found ilmenite-rich basalts at multiple locations on the Moon. Most of these basalts were extremely old, forming at least 3 billion years ago. These rocks often contained over 10% titanium dioxide (TiO2). Minerals present in these rocks were mostly feldspars and pyroxenes, with ilmenite next in abundance. Some samples of lunar regolith contained significant amounts of ilmenite. It…
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Uses of Ilmenite
Ilmenite is the primary ore of titanium metal. Small amounts of titanium combined with certain metals will produce durable, high-strength, lightweight alloys. These alloys are used to manufacture a wide variety high-performance parts and tools. Examples include: aircraft parts, artificial joints for humans, and sporting equipment such as bicycle frames. About 5% of the ilmenite…
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Physical Properties of Ilmenite
Ilmenite is a black mineral with a submetallic to metallic luster. With just a glance it can easily be confused with hematite and magnetite. The differentiation is easy. Hematite has a red streak, while ilmenite has a black streak. Magnetite is strongly magnetic, while ilmenite is not magnetic. Occasionally ilmenite is weakly magnetic, possibly from small amounts of included magnetite.…
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Chemical Composition of Ilmenite
Ilmenite’s ideal chemical composition is FeTiO3. However, it often departs from that composition by containing variable amounts of magnesium or manganese. These elements substitute for iron in complete solid solution. A solid solution series exists between ilmenite (FeTiO3) and geikielite (MgTiO3). In this series, variable amounts of magnesium substitutes for iron in the mineral’s crystal…
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Geologic Occurrence
Most ilmenite forms during the slow cooling of magma chambers and is concentrated through the process of magmatic segregation. A large underground magma chamber can take centuries to cool. As it cools, crystals of ilmenite will begin forming at a specific temperature. These crystals are heavier than the surrounding melt and sink to the bottom of the…
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What is Ilmenite?
Ilmenite is a common accessory mineral in igneous rocks, sediments, and sedimentary rocks in many parts of the world. Apollo astronauts found abundant ilmenite in lunar rocks and the lunar regolith. Ilmenite is a black iron-titanium oxide with a chemical composition of FeTiO3. Ilmenite is the primary ore of titanium, a metal needed to make a variety of high-performance alloys. Most of the ilmenite…
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Compositional and Structural Variations
Specimens of rhodonite that contain up to 20% calcium oxide are usually grayish brown in color and are known as “bustamite.” “Fowlerite” is the name given to specimens that contain up to 7% zinc oxide. Specimens with a brown color have usually been altered by weathering. Rhodonite is one of two minerals with a chemical…