April 23, 2024: Dwarf Fortress 50.13 has been released.
News: February 3, 2024: The February '24 Report is up.
News: February 4, 2021: Dwarf Fortress Talk #28 has been posted.
News: November 21, 2018: A new Threetoe story has been posted.
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quote:
Originally posted by Coke_Can64:
<STRONG>Umm, do you mean ****? Or is Hidden Fun Stuff actually called Hidden Fun Stuff... :confused:</STRONG>
quote:
Originally posted by gerkinzola:
<STRONG>!!!!!SPOILERS!!!!!
Hidden fun stuff are the **** the you find below ****.</STRONG>
SHHHHH!!!!! IT'S SUPPOSED TO BE A SURPRISE!!!!!
no immigrants
no immagrants
few immigrants
pop cap too low
migrants
There, should be easier to find using the anemic "search" in the future.
quote:
Originally posted by GRead:
<STRONG>have you messed with the baby caps? they're bugged right now and affect immigrants as well, so if you turn babies to nil and your pop cap to 80, you'll barely get any immigrants at all.</STRONG>
Thank you! Now, hopefully, I'll get some of these hauling jobs done!
[ April 27, 2008: Message edited by: PTTG?? ]
quote:
Originally posted by Metalax:
<STRONG>Very nice work. Claystone and Horn silver seem to have been missed out.</STRONG>
Hmm... That's odd. I'll add them.
CLAYSTONE:
Claystone (pronounced /ˈkleɪstoʊn/) is a geological term used to describe a sedimentary rock that is composed primarily of clay-sized particles (less than 1/256 millimetre in diameter). It does not refer to those rocks that are laminated or easily split into thin layers (clay shales). Claystones are distinct from mudstones, which are partly hardened muds that slake when wetted; claystone is fully-hardened material.
HORN SILVER:
Chlorargyrite is the mineral form of silver chloride (AgCl). Chlorargyrite occurs as a secondary mineral phase in the oxidation of silver mineral deposits. It crystallizes in the isometric - hexoctahedral crystal class. Typically massive to columnar in occurrence it also has been found as colorless to variably yellow cubic crystals. The color changes to brown or purple on exposure to light. It is quite soft with a Mohs hardness of 1 to 2 and dense with a specific gravity of 5.55. It is also known as cerargyrite and, when weathered by desert air, as horn silver. Chlorargyrite is water insoluble.
Fullerite (solid state)
The C60 fullerene in crystalline form
The C60 fullerene in crystalline form
Fullerites are the solid-state manifestation of fullerenes and related compounds and materials.
Polymerized single walled nanotubes (P-SWNT) are a class of fullerites and are comparable to diamond in terms of hardness. However, due to the way that nanotubes intertwine, P-SWNTs do not have the corresponding crystal lattice that makes it possible to cut diamonds neatly. This same structure results in a less brittle material, as any impact that the structure sustains is spread out throughout the material. Because nanotubes are still very expensive to produce in useful quantities[citation needed], uses for a material lighter and stronger than steel will have to wait until nanotube production becomes more economically viable.
Lighter, stronger, sharper, and more expensive than steel, eh? Sound familiar?
The atomic structure of carbon fiber is similar to that of graphite, consisting of sheets of carbon atoms (graphene sheets) arranged in a regular hexagonal pattern. The difference lies in the way these sheets interlock. Graphite is a crystalline material in which the sheets are stacked parallel to one another in regular fashion. The chemical bonds between the sheets are relatively weak Van der Waals forces, giving graphite its soft and brittle characteristics. Depending upon the precursor to make the fiber, carbon fiber may be turbostratic or graphitic, or have a hybrid structure with both graphitic and turbostratic parts present. In turbostratic carbon fiber the sheets of carbon atoms are haphazardly folded, or crumpled, together. Carbon fibers derived from Polyacrylonitrile (PAN) are turbostratic, whereas carbon fibers derived from mesophase pitch are graphitic after heat treatment at temperatures exceeding 2200 C. Turbostratic carbon fibers tend to have high tensile strength, wheresas heat-treated mesophase-pitch-derived carbon fibers have high Young's modulus and high thermal conductivity.
ADAMANTINE WEAPONS:
Carbon Fiber Sword
War Axe
And the Deadliest Item Known to all of Dwarfkind; the Adamantine Arrow:
CALCITE
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). The other polymorphs are the minerals aragonite and vaterite. It has a Mohs hardness of 3, a specific gravity of 2.71, and its luster is vitreous in crystallized varieties. Color is white or none, though shades of gray, red, yellow, green, blue, violet, brown, or even black can occur when the mineral is charged with impurities.
Calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. It is perhaps best known because of its power to produce strong double refraction of light, such that objects viewed through a clear piece of calcite appear doubled in all of their parts—a phenomenon first described by Rasmus Bartholin. A beautifully transparent variety used for optical purposes comes from Iceland, called Iceland spar.
SALTPETER
(Potassium nitrate)
Potassium nitrate is a chemical compound with the chemical formula KNO3. A naturally occurring mineral source of nitrogen, KNO3 constitutes a critical oxidizing component of black powder gunpowder. In the past it was also used for several kinds of burning fuses, including slow matches. Since potassium nitrate readily precipitates, urine was a significant source, through various malodorous means, from the Late Middle Ages and Early Modern era through the 19th century. Potassium nitrate is the oxidizing component of black powder. Before the large-scale industrial fixation of nitrogen through the Haber process, major sources of potassium nitrate were the deposits crystallizing from cave walls and the draining of decomposing organic material. Potassium nitrate is also used as a fertilizer, in amateur rocket propellant, and in several fireworks such as smoke bombs, in which a mixture with sugar produces a smoke cloud of 600 times their own volume. The ratio for smoke bombs using sucrose (powdered sugar) and potassium nitrate is 40(C12H22O11):60(KNO3). It can be used as is,or consolidated into a lump by mixing with water to make a paste and allowing to dry overnight.
(Please don't take the above as encouragement to try a practical experiment, and if you do, it came from Wikipedia, not me.)
ALABASTER, ECT.
http://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Alabaster.whole.600pix.jpg/200px-Alabaster.whole.600pix.jpg
Alabaster (sometimes called satin spar) is a name applied to varieties of two distinct minerals: gypsum (a hydrous sulfate of calcium) and calcite (a carbonate of calcium). The former is the alabaster of the present day; the latter is generally the alabaster of the ancients.
The two kinds are readily distinguished from each other by their relative hardnesses. The gypsum kind is so soft as to be readily scratched by a finger-nail (Mohs hardness 1.5 to 2), while the calcite kind is too hard to be scratched in this way (Mohs hardness 3), though it does yield readily to a knife. Moreover, the calcite alabaster, being a carbonate, effervesces on being touched with hydrochloric acid, whereas the gypsum alabaster, when so treated, remains practically unaffected.
Selenite, satin spar, desert rose, and gypsum flower are the four crystalline varieties of gypsum. All gypsum varieties are very soft mineral (hardness: 2 on Mohs Scale) composed of calcium sulfate dihydrate (meaning has two molecules of water), with the chemical formula CaSO4·2H2O. Selenite can be scratched with a fingernail.
ANHYDRITE
Anhydrite is a mineral - anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The hardness is 3.5 and the specific gravity 2.9. The colour is white, sometimes greyish, bluish or purple. On the best developed of the three cleavages the lustre is pearly, on other surfaces it is vitreous. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO4·2H2O) by the absorption of water. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite and pyrite in vein deposits.
ALUNITE
Alunite, or alumstone, is a mineral that was first observed in the 15th century in Monti della Tolfa, north to Rome, where it was mined for the manufacture of alum. First called aluminilite by J.C. Delametherie in 1707, this name was contracted by François Beudant in 1824 to alunite.
Distinct crystals of alunite are rarely found in cavities in the massive material. Alunite crystallizes in the hexagonal system with crystals forming trigonal pyramids that resemble rhombohedra with interfacial angles of 90 50', so that they resemble cubes in appearance. Minute glistening crystals have also been found loose in cavities in altered rhyolite. Alunite varies in color from white to yellow gray. The hardness is 4 and the specific gravity is between 2.6 and 2.8. The mineral is a hydrated aluminium potassium sulfate, KAl3(SO4)2(OH)6. Sodium substitutes for potassium and when high in sodium it is called natroalunite. It is insoluble in water or weak acids, but soluble in sulfuric acid. Jarosite is an iron analogue in which Fe3+ replaces the aluminium. It occurs as a secondary mineral on iron sulfate ores.
NOTE:
There are only 7 images in this post. Why? Because of the special bonus mineral that gets it's own.
OLIVINE
Olivine is usually named for its typically olive-green color (thought to be a result of traces of nickel), though it may alter to a reddish color from the oxidation of iron. It has a conchoidal fracture and is rather brittle. The hardness of olivine is 6.5–7, its relative density is 3.27–3.37, and it has a vitreous luster. It is transparent to translucent.
Transparent olivine is sometimes used as a gemstone called peridot, the French word for olivine. It is also called chrysolite, from the Greek words for gold and stone. Some of the finest gem-quality olivine has been obtained from a body of mantle rocks on Zabargad island in the Red Sea.
HORNBLENDE
Hornblende is a complex inosilicate series of minerals. Hornblende is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole(A kind of common iron-rich stone).
KAOLINITE
Kaolinite is a clay mineral with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra (Deer et al., 1992). Rocks that are rich in kaolinite are known as china clay or kaolin. Kaolinite is very common on earth.
SERPENTINE
The serpentine group describes a group of common rock-forming hydrous magnesium iron phyllosilicate ((Mg, Fe)3Si2O5(OH)4) minerals; they may contain minor amounts of other elements including chromium, manganese, cobalt and nickel. In mineralogy and gemology, serpentine may refer to any of 20 varieties belonging to the serpentine group. Owing to admixture, these varieties are not always easy to individualize, and distinctions are not usually made.
ORTHOCLASE
Orthoclase (endmember formula KAlSi3O8) is an important tectosilicate mineral, which forms igneous rock. It is also known as alkali feldspar and is common in granite and related rocks.
MICROCLINE
Microcline (KAlSi3O8) is an important igneous rock forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is stable at lower temperatures than orthoclase. Microcline may be clear, white, pale-yellow, brick-red, or green; it is generally characterized by cross-hatch twinning that forms as a result of the transformation of monoclinic orthoclase into triclinic microcline. Microcline may be chemically the same as monoclinic orthoclase, but because it belongs to the triclinic crystal system, the prism angle is slightly less than right angles; hence the name "microcline" from the Greek "small slope."
RUTILE
Rutile is a mineral composed primarily of titanium dioxide, TiO2.
Rutile is the most common natural form of TiO2, with two rarer polymorphs anatase (sometimes known by the obsolete name 'octahedrite'), a tetragonal mineral of pseudo-octahedral habit; and brookite, an orthorhombic mineral.
Rutile has among the highest refractive indices of any known mineral and also exhibits high dispersion. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum.
Rutile derives its name from the Latin rutilus, red, in reference to the deep red color observed in some specimens when viewed by transmitted light.
MAGNETITE
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron(II,III) oxide and the common chemical name ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part wüstite (FeO) and one part hematite (Fe2O3). This refers to the different oxidation states of the iron in one structure, not a solid solution. Magnetite is the most magnetic of all the naturally occurring minerals on Earth, and these magnetic properties led to lodestone being used as an early form of magnetic compass.
CHROMITE
Chromite, iron magnesium chromium oxide: (Fe, Mg)Cr2O4, is an oxide mineral belonging to the spinel group. Magnesium is always present in variable amounts, also aluminium and iron substitute for chromium.
Chromite is found in peridotite and other layered ultramafic intrusive rocks and also found in metamorphic rocks such as serpentinites. Ore deposits of chromite form as early magmatic differentiates. It is commonly associated with olivine, magnetite, serpentine, and corundum.
PYROLUSITE
Pyrolusite is a mineral consisting essentially of manganese dioxide (MnO2) and is important as an ore of manganese. It is a soft, black, amorphous appearing mineral, often with a granular, fibrous or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black streak, and readily soils the fingers. The specific gravity is about 4.8.
PITCHBLENDE
Uraninite is a uranium-rich mineral with a composition that is largely UO2 (uranium dioxide), but which also contains UO3 and oxides of lead, thorium, and rare earths. It is most commonly known in the variety pitchblende (from pitch, because of its black color, and blende, a term used by German miners to denote minerals whose density suggested metal content, but whose exploitation was, at the time they were named, either impossible or not economically feasible). All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium; it was in pitchblende from the Jáchymov (then Joachimsthal, Austria-Hungary) now in the Czech Republic that Marie Curie discovered radium. Uraninite also always contains small amounts of the lead isotopes, Pb-206 and Pb-207, the end products of the decay series of the uranium isotopes U-238 and U-235 respectively. Small amounts of helium are also present in uraninite as a result of alpha decay. Helium was first found on Earth in uraninite after previously being discovered spectroscopically in the Sun's atmosphere. The extremely rare element technetium can be found in uraninite in very small quantities (about 0.2 ng/kg), produced by the spontaneous fission of uranium-238.
BAUXITE
Bauxite is the most important aluminium ore. It consists largely of the minerals gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH), together with the iron oxides goethite and hematite, the clay mineral kaolinite and small amounts of anatase TiO2. It was named after the village Les Baux-de-Provence in southern France, where it was first discovered in 1821 by geologist Pierre Berthier.
NATIVE ALUMINUM
In the Earth's crust, aluminium is the most abundant (8.13%) metallic element, and the third most abundant of all elements (after oxygen and silicon). However, because of its strong affinity to oxygen, it is not found in the elemental state but only in combined forms such as oxides or silicates. Feldspars, the most common group of minerals in the earth's crust, are aluminosilicates.
Although aluminium is an extremely common and widespread element, the common aluminium minerals are not economic sources of the metal. Almost all metallic aluminium is produced from the ore bauxite. Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions.
Bismuthinite is a mineral consisting of bismuth sulfide (Bi2S3). It is an important ore for bismuth. The crystals are steel-grey to off-white with a metallic luster. It is soft enough to be scratched with a fingernail and rather dense.
Bismuthinite forms a series with the lead, copper, bismuth mineral aikinite
REALGAR
Realgar, α-As4S4, is an arsenic sulfide mineral. It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment (As2S3). It is orange-red in colour, melts at 320 °C, and burns with a bluish flame releasing fumes of arsenic and sulfur. Realgar is soft with a Mohs hardness of 1.5 to 2 and has a specific gravity of 3.5. Its molecular weight is 106.99. Its streak is orange colored. Realgar has a sub-metallic luster. Hmm... make a stockpile of Reakgar near your entrance, pout magma on it when the Goblins come...
ORPIMENT
Orpiment is an orange to yellow mineral that is found worldwide, and occurs as a sublimation product in volcanic fumaroles, low temperature hydrothermal veins, hot springs and as a byproduct of the decay of another arsenic mineral, realgar. It is often found in association with realgar. It takes its name from the Latin auripigmentum (aurum − gold + pigmentum − pigment) because of its deep yellow color.
STIBNITE
Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. It forms grey orthorhombic crystals of hardness 2. It is the most important source for the rare metaloid antimony. Antimony (pronounced /ˈæntɪmoʊni/ (US), /ˈæntɪməni/ (UK)) is a chemical element with the symbol Sb (Latin: stibium, meaning "mark") and atomic number 51. A metalloid, antimony has four allotropic forms. The stable form of antimony is a blue-white metalloid. Yellow and black antimony are unstable non-metals. Antimony is used in flame-proofing, paints, ceramics, enamels, a wide variety of alloys, electronics, and rubber.
MARCASITE
The mineral marcasite, sometimes called white iron pyrite, is iron sulfide (FeS2). Marcasite is often mistakenly confused with pyrite, but marcasite is lighter and more brittle. Specimens of marcasite often crumble and break up due to the unstable crystal structure, and it is this crystal structure that is the main difference between marcasite and pyrite. Though marcasite has the same chemical formula as pyrite, it crystallizes in a different crystal system, thereby making it a separate mineral. In jewelry, pyrite used as a gem is improperly termed "marcasite". True marcasite is never used as a gem, due to its brittle and chemically unstable structure.
SYLVITE
Sylvite is potassium chloride (KCl) in natural mineral form. It forms crystals in the isometric system very similar to normal rock salt, halite (NaCl). (The two are, in fact, isomorphous. [3] Sylvite is colorless to white with shades of yellow and red due to inclusions. It has a Mohs hardness of 2.5 and a specific gravity of 1.99. It has a refractive index of n=1.490) [4]. Sylvite has a salty taste with a distinct bitterness. (What?)
Sylvite is one of the last evaporite minerals to precipitate out of solution. As such, it is only found in very dry saline areas. Its principal use is as a potassium fertilizer.
CRYOLITE
Cryolite (Na3AlF6, sodium hexafluoroaluminate) is an uncommon mineral of very limited natural distribution. It is mostly identified with the once large deposit at Ivigtût on the west coast of Greenland, which ran out in 1987.
It was historically used as an ore of aluminium and later in the electrolytic processing of the aluminium rich oxide ore bauxite (itself a combination of aluminium oxide minerals such as gibbsite, boehmite and diaspore). The difficulty of separating aluminium from oxygen in the oxide ores was overcome by the use of cryolite as a flux to dissolve the oxide mineral(s). Cryolite itself melts below 900°C (1173 Kelvin) and can dissolve aluminium oxides sufficiently well to allow easy extraction of the aluminium by electrolysis. Considerable energy is still required for both heating the materials and the electrolysis, but it is much more energy-efficient than melting the oxides themselves. Now, as natural cryolite is too rare to be used for this purpose, synthetic sodium aluminium fluoride is produced from the common mineral fluorite for this purpose.
PERICLASE
Periclase occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. It is a cubic form of magnesium oxide (MgO).
The old term for the mineral is magnesia. Stones from the Magnesia region in ancient Anatolia contained both magnesium oxide and hydrated magnesium carbonate as well as iron oxides (such as magnetite). Thus these stones, called Stones from Magnesia in antiquity, with their unusual magnetic properties were the reason the terms magnet and magnetism were coined. Periclase is usually found in marble and pure periclase is colorless.
28 more minerals left. Then, mebby I'll explain the dirt types.
[ May 03, 2008: Message edited by: PTTG?? ]
TETRAHEDRITE
Tetrahedrite gets its name from the distinctive tetrahedron shaped cubic crystals. The mineral usually occurs in massive form, it is a steel grey to black metallic mineral with Mohs hardness of 3.5 to 4 and specific gravity of 4.6 to 5.2.
It occurs in low to moderate temperature hydrothermal veins and in some contact metamorphic deposits. It is a minor ore of copper and associated metals. It was first described in 1845 for occurrences in Freiberg, Saxony, Germany.
GYPSUM
Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as early as the Permian age.[3] Gypsum is deposited in lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near surface exposures. It is often associated with the minerals halite and sulfur.
TALC
Talc (derived from the Persian via Arabic talq) is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg3(SiO3)4 or Mg3Si4O10(OH)2. In loose form, it is the widely used substance known as talcum powder. It occurs as foliated to fibrous masses, its monoclinic crystals being so rare as to be almost unknown. It has a perfect basal cleavage, and the folia are non-elastic, although slightly flexible. It is sectile and very soft, with a hardness of 1 (Talc is the softest of the Mohs' scale of mineral hardness, and can be easily scratched by a fingernail). It has a specific gravity of 2.5–2.8, a clear or dusty luster, and is translucent to opaque. Its colour ranges from white to grey or green and it has a distinctly greasy feel. Its streak is white.
JET: See Lignite (yes, technically, they are the same. Jet is merely highter quality)
PUDDINGSTONE: See Conglomerate.
PETRIFIED WOOD:
Petrified wood is a type of fossil: it consists of fossil wood where all the organic materials have been replaced with minerals (most often a silicate, such as quartz), while retaining the original structure of the wood. The petrifaction process occurs underground, when wood becomes buried under sediment and is initially preserved due to a lack of oxygen. Mineral-rich water flowing through the sediment deposits minerals in the plant's cells and as the plant's lignin and cellulose decay away, a stone mould forms in its place.
Elements such as manganese, iron and copper in the water/mud during the petrification process give petrified wood a variety of color ranges. Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on a yellow, red or other tint.
GRAPHITE
The mineral graphite, as with diamond, is a form of carbon. It was named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): "to draw/write", for its use in pencils, where it is commonly called lead, as distinguished from the actual metallic element lead. Unlike diamond, graphite is an electrical conductor, and can be used, for instance, in the electrodes of an arc lamp. Graphite holds the distinction of being the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. Graphite may be considered the highest grade of coal, just above anthracite and alternatively called meta-anthracite, although it is not normally used as fuel because it is hard to ignite.
BRIMSTONE
At room temperature, sulfur is a soft bright yellow solid. Elemental sulfur has only a faint odor, similar to that of matches. The odor associated with rotten eggs is due to hydrogen sulfide (H2S) and organic sulfur compounds rather than elemental sulfur. Sulfur burns with a blue flame that emits sulfur dioxide, notable for its peculiar suffocating odor.
KIMBERLITE
is a type of igneous rock best known for sometimes containing diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an 83.5 carat diamond in 1871 spawned a diamond rush.
Kimberlite occurs in the Earth's crust in vertical structures known as kimberlite pipes. Kimberlite pipes are the most important source of mined diamonds today. The general consensus reached on kimberlites is that they are formed deep within the mantle, at between 150 and 450 kilometres depth, from anomalously enriched exotic mantle compositions, and are erupted rapidly and violently, often with considerable carbon dioxide and other volatile components. It is this depth of melting and generation which makes kimberlites prone to hosting diamond xenocrysts.
[ May 03, 2008: Message edited by: PTTG?? ]
SPHALERITE
Sphalerite ((Zn,Fe)S) is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides along with calcite, dolomite, and fluorite. Miners have also been known to refer to sphalerite as zinc blende, mock lead, false galena and black-jack.
CASSITERITE
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite is the chief ore of tin today.Most sources of cassiterite today are found in alluvial or placer deposits containing the resistant weathered grains. The best source of primary cassiterite is the tin mines of Bolivia, where it is found in hydrothermal veins. Cassiterite is a widespread minor constituent of igneous rocks. The Bolivia veins and the old exhausted workings of Cornwall, England, are concentrated in high temperature quartz veins and pegmatites associated with granitic intrusives.
BITUMINOUS COAL
Bituminous coal is a relatively soft coal containing a tar-like substance called bitumen. It is of higher quality than lignite coal but poorer quality than anthracite coal.
Bituminous coal is an organic sedimentary rock formed by diagenetic and submetamorphic compression of peat bog material.
Bituminous coal has been compressed and heated so that its primary constituents are the macerals vitrinite, exinite, etc. The carbon content of bituminous coal is around 60-80%; the rest is composed of water, air, hydrogen, and sulfur, which have not been driven off from the macerals.
LIGNITE
Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad, is the lowest rank of coal and used almost exclusively as fuel for steam-electric power generation. It is brownish-black and has a high inherent moisture content, sometimes as high as 66 percent, and very high ash content compared with bituminous coal. It is also a heterogeneous mixture of compounds for which no single structural formula will suffice.
PLATINUM
Platinum is an extremely rare metal, occurring as only 0.003 ppb in the Earth's crust, and is 30 times rarer than gold. If all the world's platinum reserves were poured into one Olympic-size swimming pool, it would be just deep enough to cover one's ankles. Gold would fill more than three such pools. Due to its rarity, greater difficulty to work with and the need to alloy it with (at the time) an even more expensive metal iridium, platinum was only used in a limited way in jewelry at the end of the 19th century. This changed at beginning of the 20th century when most diamond ring mountings and most exclusive jewelry were almost completely made of platinum.[4] From 1875 to 1960 the SI unit of length (the standard metre) was defined as the distance between two lines on a standard bar of an alloy of ninety percent platinum and ten percent iridium, measured at 0 degrees Celsius.
CINNABAR
Cinnabar, sometimes written cinnabarite, is a name applied to red mercury(II) sulfide (HgS), or native vermilion, the common ore of mercury. The name comes from the Greek - "kinnabari" - used by Theophrastus, and was probably applied to several distinct substances. Other sources say the word comes from the Persian zinjifrah, a word of uncertain origin. In Latin it was known as minium, meaning also "red lead" - a word probably borrowed from Iberian[2] (cf. Basque armineá "cinnabar"). Generally cinnabar occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs.
COBALTITE
Cobaltite is a sulfosalt mineral composed of cobalt, arsenic and sulfur, CoAsS. It contains up to 10 percent iron and variable amounts of nickel.[3] Structuraly it resembles pyrite (FeS2) with one of the sulfur atoms replaced by an arsenic atom.
Although rare it is mined as a significant source of the strategically important metal cobalt. Secondary weathering incrustations of erythrite, hydrated cobalt arsenate, are common.
The name is from the German, Kobold, "underground spirit" in allusion to the refusal of cobaltiferous ores to smelt properly.
[ April 26, 2008: Message edited by: PTTG?? ]
