the mineral marcasite, sometimes called “white iron pyrite”, is iron sulfide with orthorhombic crystal structure. it is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. both structures do have in common that they contain the disulfide s22− ion having a short bonding distance between the sulfur atoms. the structures differ in how these di-anions are arranged around the fe2 cations. marcasite is lighter and more brittle than .
the mohs scale of mineral hardness / m oʊ z / is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. created in 1812 by german geologist and mineralogist friedrich mohs, it is one of several definitions of hardness in materials science, some of which are more quantitative.
the color of those objects composed of pyrite is not known. all of the specimens of these objects, which were cut open by heinrich, exhibited an extremely well-defined radial structure terminating on either the center or centers of a klerksdorp sphere. some of these objects exhibit well-defined and parallel latitudinal grooves or ridges. even .
euhedral crystals also known as idiomorphic or automorphic crystals are those that are well-formed, with sharp, easily recognised faces.the opposite is anhedral also known as xenomorphic or allotriomorphic : a rock with an anhedral texture is composed of mineral grains that have no well-formed crystal faces or cross-section shape in thin section. .
by the classic period c.ad 250–900 iron pyrite was the mineral of choice for fashioning mirrors. instead of crafting the mirror from a single piece of pyrite, pre-cut pieces of pyrite would be fixed to a piece of slate, forming a mosaic mirror fashioned from finely fitted pieces.
goethite feo oh ; / ˈ ɡ ɜːr t aɪ t / is an iron-bearing hydroxide mineral of the diaspore group. it is found in soil and other low-temperature environments such as sediment. goethite has been well known since ancient times for its use as a pigment brown ochre .evidence has been found of its use in paint pigment samples taken from the caves of lascaux in france.
a carbon flaw is a blemish present within a diamond crystalline form of carbon, usually seen as a black spot.the blemish may be microscopic or visible to the naked eye. the spots are undesirable imperfections since they can be seen more easily than other flaws.
segnitite, named after australian mineralogist, gemologist and petrologist edgar ralph segnit, is a lead iron iii arsenate mineral.the mineral was named after e. r. segnit due to his contributions to australian mineralogy.segnitite was first found in the broken hill ore deposit in broken hill, new south wales, australia.in 1991, segnitite was approved as a new mineral.
hornfels is the group name for a set of contact metamorphic rocks that have been baked and hardened by the heat of intrusive igneous masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable. these properties are due to fine grained non-aligned crystals with platy or prismatic habits.the term is derived from the german word hornfels, meaning .
iron pyrite. voting period is over. please don't add any new votes. voting period ends on 4 oct 2010 at 03:51:43 utc original - a mass of intergrown pyrite crystals. pyrite is commonly known as fool's gold. reason a cool image that accurately portrays the subject. previous nomination here didn't garner enough votes. articles in which this image appears pyrite fp category for this image .
under normal conditions, pyrite would form cubes or pyritohedrons. in mineralogy , crystal habit is the characteristic external shape of an individual crystal or crystal group. a single crystal's habit is a description of its general shape and its crystallographic forms , plus how well developed each form is.
i wonder if iron pyrite, known as 'fool's gold' would work. sturat 04:09, 23 june 2014 utc pyrite does look like gold, but it oxidizes in air, thus decomposing to iron oxide and sulfuric acid -- this reaction irreversibly discolors the repair, and the sulfuric acid may go on to damage the article. 188.8.131.52 06:19, 23 june 2014 utc
in the field of mineralogy, fracture is the texture and shape of a rock's surface formed when a mineral is fractured.minerals often have a highly distinctive fracture, making it a principal feature used in their identification. fracture differs from cleavage in that the latter involves clean splitting along the cleavage planes of the mineral's crystal structure, as opposed to more general .
chalcopyrite is the most important copper ore. chalcopyrite ore occurs in a variety of ore types, from huge masses as at timmins, ontario, to irregular veins and disseminations associated with granitic to dioritic intrusives as in the porphyry copper deposits of broken hill, the american cordillera and the andes.
terrestrial analogue sites also called 'space analogues' are places on earth with assumed past or present geological, environmental or biological conditions of a celestial body such as the moon or mars.analogue sites are used in the frame of space exploration to either study geological or biological processes observed on other planets, or to prepare astronauts for surface extra-vehicular .
a concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. concretions are often ovoid or spherical in shape, although irregular shapes also occur. the word 'concretion' is derived from the latin con meaning 'together' and crescere meaning 'to grow'. concretions form within layers of sedimentary strata that have already been deposited. they usually form early in the burial history of
arsenopyrite is an iron arsenic sulfide feass . it is a hard mohs 5.5-6 metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1.when dissolved in nitric acid, it releases elemental sulfur.when arsenopyrite is heated, it produces poisonous sulfur and arsenic fumes which can be fatal if inhaled in large quantities.
iron pyrite is unstable at earth's surface: iron pyrite exposed to atmospheric oxygen and water decomposes into iron oxides and sulfate. this process is accelerated by the action of acidithiobacillus bacteria which oxidize pyrite to produce ferrous iron, sulfate, and protons h .