Search results
Results from the WOW.Com Content Network
Pyrite cubic crystals on marl from Navajún, La Rioja, Spain (size: 95 by 78 millimetres [3.7 by 3.1 in], 512 grams [18.1 oz]; main crystal: 31 millimetres [1.2 in] on edge) Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold.
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.
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]
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.
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.
These include ε-FeOOH, which has an orthorhombic crystal structure, [10] a cubic pyrite-type polymorph with [11] or without losing hydrogen [12] and an ultradense hexagonal structure. [13] Goethite has the same crystal structure as diaspore, the analogous aluminium oxide-hydroxide mineral. Oxygen and hydroxide ions form a hexagonal close ...
The term "shungite" has evolved substantially since was originally used in 1879 to describe a black substance with more than 98% carbon found in veins near its type locality of Shunga.
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.