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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 color has also led to the ...
[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.
Pyrrhotite (pyrrhos in Greek meaning "flame-coloured") is an iron sulfide mineral with the formula Fe (1-x) S (x = 0 to 0.125). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is
This disintegration of marcasite in mineral collections is known as "pyrite decay". When a specimen goes through pyrite decay, the marcasite reacts with moisture and oxygen in the air, the sulfur oxidizing and combining with water to produce sulfuric acid that attacks other sulfide minerals and mineral labels.
Thus, the ideal formula one would expect for a spinel like carrollite is Cu 2+ Co 3+ 2 S 2− 4, but as in the case of copper sulfides in general the oxidation state of the copper atom is 1+, not 2+. An assignment of valences as Cu + Co 3+ 2 S 1.75− 4 is more appropriate; this was confirmed in a study of 2009. [ 11 ]
Galena with baryte and pyrite from Cerro de Pasco, Peru; 5.8 cm × 4.8 cm × 4.4 cm (2.3 in × 1.9 in × 1.7 in) Galena is the main ore of lead, used since ancient times, [7] since lead can be smelted from galena in an ordinary wood fire. [8]
Leaf anatomy in most C 4 plants. A: Mesophyll cell B: Chloroplast C: Vascular tissue D: Bundle sheath cell E: Stoma F: Vascular tissue 1. CO 2 is fixed to produce a four-carbon molecule (malate or aspartate). 2. The molecule exits the cell and enters the bundle sheath cells. 3. It is then broken down into CO 2 and pyruvate.
It is a hard (Mohs 5.5–6) [5] metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. [1] When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it produces sulfur and arsenic vapor. With 46% arsenic content, arsenopyrite, along with orpiment, is a principal ore ...