Latest Mineral Stories
A new study focusing on the mineral molybdenite could provide new insight into the way that various geological and biological processes have resulted in changes to the Earth’s chemistry over the years.
This classical theory of crystal formation, which occurs widely in nature and in the chemical industry, was under fire for some years, but is saved now.
Mineral evolution posits that Earth's near-surface mineral diversity gradually increased through an array of chemical and biological processes.
Aragonite is a polymorph of the mineral calcite, both having the chemical composition CaCO3. Its structure differs from calcite and leads to a different crystal shape, an orthorhombic system with acicular crystals. By repeated twinning pseudo-hexagonal forms result. It may be columnar or fibrous, occasionally in branching stalactitic forms called flos-ferri (flowers of iron) from their association with the ores at the Carthinian iron mines. The type location for aragonite is Molina de...
Augite is a mafic mineral described chemically as (Ca, Na)(Mg, Fe, Al)(Al, Si)2O6 or calcium sodium magnesium iron aluminium silicate. Structurally, it is a solid solution of the pyroxene group which also contains diopside and hedenbergite. The crystals are monoclinic and prismatic. It is found in igneous rocks such as gabbros and basalts, and in metamorphic rocks from hydrothermal vents. Occasional specimens have a shiny appearance that give rise to the mineral's name, which is from the...
Celestite (SrSO4) is a mineral consisting of strontium sulfate. The mineral is also known as celestine and is named for its occasional delicate blue color. Celestite occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in sedimentary rocks, often associated with the minerals gypsum, anhydrite, and halite. The mineral is found worldwide, usually in small quantities. Pale blue crystal specimens are found in Madagascar.
Colemanite (Ca2B6O11Â·5H2O) is a borate mineral found in evaporite deposits. Colemanite is a secondary mineral that forms when borax is deposited, and then regularly covered with boron containing water. The boron remains after the water evaporates, and the boron and borax eventually form other minerals as for example Colemanite. It was named after William T. Coleman (1824-1893), owner of the mine where it was first found.
Galena is a lead ore. This article describes Galena's mineral properties. In its chemically purified form, Galena is known as Lead Sulfide; refer to that article for chemical and industrial uses. Galena is one of the most abundant and widely distributed sulfide minerals, and is the most common ore of lead. Crystals are usually cubic, sometimes octahedral. It is often associated with the minerals sphalerite and fluorite. Galena deposits sometimes contain significant amounts of silver as an...
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