-
Uses of Hematite (Pigment)
The name hematite is from the Greek word “haimatitis” which means “blood-red.” That name stems from the color of hematite when it has been crushed to a fine powder. Primitive people discovered that hematite could be crushed and mixed with a liquid for use as a paint or cosmetic. Cave paintings, known as “pictographs,” dating…
-
Uses of Hematite (Iron Ore)
Hematite is the world’s most important ore of iron. Although magnetite contains a higher percentage of iron and is easier to process, hematite is the leading ore because it is more abundant and present in deposits in many parts of the world. Hematite is mined in some of the largest mines in the world. These…
-
Hematite on Mars?
NASA has discovered that hematite is one of the most abundant minerals in the rocks and soils on the surface of Mars. An abundance of hematite in Martian rocks and surface materials gives the landscape a reddish brown color and is why the planet appears red in the night sky. It is the origin of Mars’ “Red…
-
Geologic Occurrence
Hematite is found as a primary mineral and as an alteration product in igneous, metamorphic, and sedimentary rocks. It can crystallize during the differentiation of a magma or precipitate from hydrothermal fluids moving through a rock mass. It can also form during contact metamorphism when hot magmas react with adjacent rocks. The most important hematite…
-
Composition of Hematite
Pure hematite has a composition of about 70% iron and 30% oxygen by weight. Like most natural materials, it is rarely found with that pure composition. This is particularly true of the sedimentary deposits where hematite forms by inorganic or biological precipitation in a body of water. Minor clastic sedimentation can add clay minerals to…
-
Physical Properties of Hematite
Hematite has an extremely variable appearance. Its luster can range from earthy to submetallic to metallic. Its color ranges include red to brown and black to gray to silver. It occurs in many forms that include micaceous, massive, crystalline, botryoidal, fibrous, oolitic, and others. Even though hematite has a highly variable appearance, it always produces…
-
What is Hematite?
Hematite is one of the most abundant minerals on Earth’s surface and in the shallow crust. It is an iron oxide with a chemical composition of Fe2O3. It is a common rock-forming mineral found in sedimentary, metamorphic, and igneous rocks at locations throughout the world. Hematite is the most important ore of iron. Although it was once mined at thousands of locations around the world,…
-
Uses of Molybdenum Metal
Molybdenite is the primary ore of molybdenum metal, which is an extremely important metal for making specialty alloys. Small amounts of molybdenum added to steel and other alloys can significantly increase their toughness, heat resistance, hardness, strength, and resistance to corrosion. Molybdenum is an important ingredient in making stainless steel, alloy steels, and a variety…
-
Lubricant Uses of Molybdenite
Molybdenite has a layered atomic structure in which a sheet of molybdenum atoms is sandwiched between two sheets of sulfur. The bonds between the molybdenum and sulfur atoms are very strong. These S-Mo-S layers are stacked one on top of another, but the bonds between the layers are very weak. The bonds between the layers…
-
Molybdenite as an Ore of Rhenium
With an average crustal abundance of less than one part per billion, rhenium is one of the rarest elements in Earth’s crust. Most of the world’s known rhenium resource exists within the mineral molybdenite, substituting for molybdenum atoms in the mineral’s crystal lattice. Rhenium has one of the most surprising and indirect methods of production…