Search results
Results from the WOW.Com Content Network
[1] [2] The group is named for its most common member, pyrite (fool's gold), which is sometimes explicitly distinguished from the group's other members as iron pyrite. Pyrrhotite (magnetic pyrite) is magnetic, and is composed of iron and sulfur, but it has a different structure and is not in the pyrite group.
Pyrite occurs both as a primary mineral, present in the original sediments, and as a secondary mineral, deposited during diagenesis. [2] Pyrite and marcasite commonly occur as replacement pseudomorphs after fossils in black shale and other sedimentary rocks formed under reducing environmental conditions. [58] Pyrite is common as an accessory ...
Also, the mineral pyrite is both the most common and most abundant sulfide mineral in the Earth's crust. [6] If rocks containing pyrite undergo metamorphism, there is a gradual release of volatile components like water and sulfur from pyrite. [6] The loss of sulfur causes pyrite to recrystallize into pyrrhotite. [6]
The oxide mineral class includes those minerals in which the oxide anion (O 2−) is bonded to one or more metal alloys. The hydroxide -bearing minerals are typically included in the oxide class. Minerals with complex anion groups such as the silicates , sulfates , carbonates and phosphates are classed separately.
Từ điển bách khoa toàn thư Việt Nam (Encyclopedia of Vietnam), a state-sponsored encyclopedia which was published in 2005. Vietnamese Wikipedia, a project of the Wikimedia Foundation. Vietnam War encyclopedias. Encyclopedic works and encyclopedias focused on Vietnam War-related topics.
Từ điển bách khoa Việt Nam (lit: Encyclopaedic Dictionary of Vietnam) is a state-sponsored Vietnamese-language encyclopedia that was first published in 1995. It has four volumes consisting of 40,000 entries, the final of which was published in 2005. [1] The encyclopedia was republished in 2011.
Sperrylite is a platinum arsenide mineral with the chemical formula PtAs 2 and is an opaque metallic tin white mineral which crystallizes in the isometric system with the pyrite group structure. It forms cubic, octahedral or pyritohedral crystals in addition to massive and reniform habits.
The more general crystal structure describes materials of the type A 2 B 2 O 6 and A 2 B 2 O 7 where the A and B species are generally rare-earth or transition metal species; e.g. Y 2 Ti 2 O 7.The pyrochlore structure is a super structure derivative of the simple fluorite structure (AO 2 = A 4 O 8), where the A and B cations are ordered along ...